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Head Cases #2
Inside Man
10 hours, 18 minutes
In this sequel to McMahon's electrifying series debut, Head Cases, Gardner Camden and the PAR team return to investigate potentially connected cases.
FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve.
PAR’s latest case involves a militia group stockpiling weapons. When their confidential informant in the case is killed, it quickly becomes clear that the militia did not kill him.
As the squad looks into the evidence surrounding his murder, an unidentified man is caught on camera with their informant. This mystery man’s picture is connected to another case at the FBI, an unsolved series of murdered women, buried in the ground in north Florida. Could they have uncovered a serial killer? And if so, what is his connection to their C.I.?
As PAR juggles an investigation into both the dead women and the militia, they enroll a new informant, only to find the case escalating in dangerous ways. How will PAR handle a case that increasingly looks like a terrorist plot? And in the serial case, with no puzzles or witnesses, and few leads, how will a group set up to decode riddles be successful?
In this sequel to McMahon's electrifying series debut, Head Cases, Gardner Camden and the PAR team return to investigate potentially connected cases.
FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve.
PAR’s latest case involves a militia group stockpiling weapons. When their confidential informant in the case is killed, it quickly becomes clear that the militia did not kill him.
As the squad looks into the evidence surrounding his murder, an unidentified man is caught on camera with their informant. This mystery man’s picture is connected to another case at the FBI, an unsolved series of murdered women, buried in the ground in north Florida. Could they have uncovered a serial killer? And if so, what is his connection to their C.I.?
As PAR juggles an investigation into both the dead women and the militia, they enroll a new informant, only to find the case escalating in dangerous ways. How will PAR handle a case that increasingly looks like a terrorist plot? And in the serial case, with no puzzles or witnesses, and few leads, how will a group set up to decode riddles be successful?
Audiobook
First published January 13, 2026
220 people are currently reading
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About the author
John McMahon
5 books759 followersJohn McMahon is the author of THE GOOD DETECTIVE and THE EVIL MEN DO, both featuring Georgia detective P.T. Marsh.
The New York Times Book Review called McMahon “one of those rare writers who seems to have sprung out of nowhere” and whose debut novel is “pretty much perfect.”
In his role as an ad agency creative director, he has won a Gold Clio for his work on Fiat, and he’s written a Super Bowl spot for Alfa Romeo.
He currently lives in Southern California with his family and two rescue animals.
The New York Times Book Review called McMahon “one of those rare writers who seems to have sprung out of nowhere” and whose debut novel is “pretty much perfect.”
In his role as an ad agency creative director, he has won a Gold Clio for his work on Fiat, and he’s written a Super Bowl spot for Alfa Romeo.
He currently lives in Southern California with his family and two rescue animals.
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Displaying 1 - 30 of 419 reviews
December 9, 2025
If you enjoy puzzles and crime thrillers, then look no further than this series. John McMahon continues his winning Head Cases series with its second book,
Inside Man.
The FBI’s Patterns and Recognition (PAR) unit has relocated to Miami, Florida. The squad has been working on a case involving a militia group stockpiling weapons. When their confidential informant in the case is killed, it seems the militia didn’t murder him.
They find an unidentified man caught on camera with their informant. Is he the killer? He is also connected to an FBI unsolved case involving a series of murdered woman found buried in north Florida. Are the cases connected? If so, how? Can they find a new informant for the original case? Can they handle both cases? Should they attempt to do that with only four agents, including their leader?
FBI Agent Gardner Camden is the team leader. Gardner is intelligent, confident, all business, and has an eidetic memory. He thinks in terms of layers and patterns, avoids friendships with most, and can come across as arrogant. He has an affinity for riddles, puzzles, and codes. I enjoyed how the author brought to life both the personal and professional lives of Gardner. As readers learn his background, it provides insight into his thoughts, behaviors, and actions. It was fascinating to see how Gardner’s mind worked to solve the various puzzles. Joanne “Shooter” Harris is his current partner. She has an offbeat humor, can track, and shoot, and was part of an Olympic shooting team before she joined the FBI. Richie Brancato joined the team straight out to the academy. He’s the rookie and he’s also the grandson of a former FBI director. Cassie Pardo is Gardner’s former partner. She is a mathematician, energetic, uses slang, and is mentoring Richie. A couple of other characters from the first book show up along with several new ones.
The author is a superb storyteller who kept me rapidly turning the pages with a fabulous plot and gripping scenes. I was immediately intrigued by the storyline and the complexities in the plot. Full of suspense, this thriller mainly looks at the case through the eyes of Gardner. It was also intriguing to see Gardner realize he should be doing certain things as a manager, but couldn’t seem to pull it off smoothly.
The well-developed characters were brimming with personality. The story grips readers from beginning to end, keeping them on their toes trying to see the connections between the two cases. There was always something new going on, whether it was a change in location, a personal moment, an investigative task, or an action scene. There’s never a dull moment with the PAR unit.
Overall, this was a compelling and dynamic story with excellent characterization, good pacing, and a great plot that includes solid procedural details. I’m a huge fan of the series and can’t wait to read the next book in the series. Those who enjoy crime thrillers and FBI investigations with extraordinary and unusual characters, as well as those who enjoy solving puzzles, will likely enjoy this novel.
St. Martin’s Press – Minotaur Books and John McMahon provided a complimentary digital ARC of this novel via NetGalley. All thoughts and opinions expressed in this review are my own. The publication date is currently set for January 13, 2026.
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My 4.58 rounded to 5 stars review is coming soon.
They find an unidentified man caught on camera with their informant. Is he the killer? He is also connected to an FBI unsolved case involving a series of murdered woman found buried in north Florida. Are the cases connected? If so, how? Can they find a new informant for the original case? Can they handle both cases? Should they attempt to do that with only four agents, including their leader?
FBI Agent Gardner Camden is the team leader. Gardner is intelligent, confident, all business, and has an eidetic memory. He thinks in terms of layers and patterns, avoids friendships with most, and can come across as arrogant. He has an affinity for riddles, puzzles, and codes. I enjoyed how the author brought to life both the personal and professional lives of Gardner. As readers learn his background, it provides insight into his thoughts, behaviors, and actions. It was fascinating to see how Gardner’s mind worked to solve the various puzzles. Joanne “Shooter” Harris is his current partner. She has an offbeat humor, can track, and shoot, and was part of an Olympic shooting team before she joined the FBI. Richie Brancato joined the team straight out to the academy. He’s the rookie and he’s also the grandson of a former FBI director. Cassie Pardo is Gardner’s former partner. She is a mathematician, energetic, uses slang, and is mentoring Richie. A couple of other characters from the first book show up along with several new ones.
The author is a superb storyteller who kept me rapidly turning the pages with a fabulous plot and gripping scenes. I was immediately intrigued by the storyline and the complexities in the plot. Full of suspense, this thriller mainly looks at the case through the eyes of Gardner. It was also intriguing to see Gardner realize he should be doing certain things as a manager, but couldn’t seem to pull it off smoothly.
The well-developed characters were brimming with personality. The story grips readers from beginning to end, keeping them on their toes trying to see the connections between the two cases. There was always something new going on, whether it was a change in location, a personal moment, an investigative task, or an action scene. There’s never a dull moment with the PAR unit.
Overall, this was a compelling and dynamic story with excellent characterization, good pacing, and a great plot that includes solid procedural details. I’m a huge fan of the series and can’t wait to read the next book in the series. Those who enjoy crime thrillers and FBI investigations with extraordinary and unusual characters, as well as those who enjoy solving puzzles, will likely enjoy this novel.
St. Martin’s Press – Minotaur Books and John McMahon provided a complimentary digital ARC of this novel via NetGalley. All thoughts and opinions expressed in this review are my own. The publication date is currently set for January 13, 2026.
---------------------------------------
My 4.58 rounded to 5 stars review is coming soon.
December 3, 2025
4 stars for a mystery thriller set in the US. This is book 2 in the series, and I have read book 1. However, this would work as a stand alone. Both books are about an FBI unit called PARS(Patterns and Recognition).
The blurb: "FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve."
This book has two plots:
1: The team are on the trail of some right wing militia folks stockpiling weapons for an unknown purpose. As they investigate, they realize that there are more serious issues involved.
2. They find a pattern of murders across multiple jurisdictions and decide that there is a serial killer murdering women.
They do solve both cases. I liked the well paced plot, believable characters and the buildup of clues leading to resolution of both cases. All of the team members have had issues with their ability to get along in a normal FBI unit and appreciate the latitude that they have in this unusual unit.
There is no graphic violence or sex. There are some curse words.
Thank You Stephen Erickson at St. Martin's Publishing Group for sending me this eARC through NetGalley.
Pub Date Jan 13 2026
The blurb: "FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve."
This book has two plots:
1: The team are on the trail of some right wing militia folks stockpiling weapons for an unknown purpose. As they investigate, they realize that there are more serious issues involved.
2. They find a pattern of murders across multiple jurisdictions and decide that there is a serial killer murdering women.
They do solve both cases. I liked the well paced plot, believable characters and the buildup of clues leading to resolution of both cases. All of the team members have had issues with their ability to get along in a normal FBI unit and appreciate the latitude that they have in this unusual unit.
There is no graphic violence or sex. There are some curse words.
Thank You Stephen Erickson at St. Martin's Publishing Group for sending me this eARC through NetGalley.
Pub Date Jan 13 2026
January 12, 2026
With a team of gifted misfits, seemingly impossible puzzles, and layers of intrigue, Inside Man was just as addictive as the first book in the series, Head Cases. Twisty, intricate, and yet easy to follow, this plot delivered a fast-paced game of cat-and-mouse that started off with a bang and didn’t let up until the very last page. You see, just when I thought it was over, Gardner figured something else out and had us on the chase yet again. As much as I loved the pursuit to work out the two potentially connected cases, however, the complex relationships and root-for-able characters were easily the stars of the show. At the top of my list of favorites in this motley crew of puzzle-solving investigators was Gardner himself. A quirky individual who’s likely neurodivergent, his flawed personality and endearing friendships made him both unforgettable and realistic at the same time.
All said and done, despite the complexity of the two supposedly unrelated cases, I couldn’t get enough of the plot or the characters. A brilliant mashup of Criminal Minds, Numb3rs, and Person of Interest, I was hooked by the theories and ideas that this bunch of geniuses worked through on the road to the truth. I mean, even the writing style itself hinted at Gardner’s personality type. Detailed and precise, it was a great counter to the often dry, witty banter between the various smart yet oddball supporting characters. Combined with the thrilling, hard-to-put-down storyline, the tense, suspense-laden feel paired well with the high-stakes action and edge-of-your seat scenes. So if you love a good crime thriller and want one that’s truly original, grab this one now. A binge-able read with both brains and heart, McMahon managed to blow my mind yet again. Rating of 4.5 stars.
SYNOPSIS:
FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve.
PAR’s latest case involves a militia group stockpiling weapons. When their confidential informant in the case is killed, it quickly becomes clear that the militia did not kill him.
As the squad looks into the evidence surrounding his murder, an unidentified man is caught on camera with their informant. This mystery man’s picture is connected to another case at the FBI, an unsolved series of murdered women, buried in the ground in north Florida. Could they have uncovered a serial killer? And if so, what is his connection to their C.I.?
As PAR juggles an investigation into both the dead women and the militia, they enroll a new informant, only to find the case escalating in dangerous ways. How will PAR handle a case that increasingly looks like a terrorist plot? And in the serial case, with no puzzles or witnesses, and few leads, how will a group set up to decode riddles be successful?
Thank you John McMahon and Minotaur Books for my complimentary copy. All opinions are my own.
PUB DATE: January 13, 2026
Content warning: dementia, murder, violence, drug overdose
All said and done, despite the complexity of the two supposedly unrelated cases, I couldn’t get enough of the plot or the characters. A brilliant mashup of Criminal Minds, Numb3rs, and Person of Interest, I was hooked by the theories and ideas that this bunch of geniuses worked through on the road to the truth. I mean, even the writing style itself hinted at Gardner’s personality type. Detailed and precise, it was a great counter to the often dry, witty banter between the various smart yet oddball supporting characters. Combined with the thrilling, hard-to-put-down storyline, the tense, suspense-laden feel paired well with the high-stakes action and edge-of-your seat scenes. So if you love a good crime thriller and want one that’s truly original, grab this one now. A binge-able read with both brains and heart, McMahon managed to blow my mind yet again. Rating of 4.5 stars.
SYNOPSIS:
FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve.
PAR’s latest case involves a militia group stockpiling weapons. When their confidential informant in the case is killed, it quickly becomes clear that the militia did not kill him.
As the squad looks into the evidence surrounding his murder, an unidentified man is caught on camera with their informant. This mystery man’s picture is connected to another case at the FBI, an unsolved series of murdered women, buried in the ground in north Florida. Could they have uncovered a serial killer? And if so, what is his connection to their C.I.?
As PAR juggles an investigation into both the dead women and the militia, they enroll a new informant, only to find the case escalating in dangerous ways. How will PAR handle a case that increasingly looks like a terrorist plot? And in the serial case, with no puzzles or witnesses, and few leads, how will a group set up to decode riddles be successful?
Thank you John McMahon and Minotaur Books for my complimentary copy. All opinions are my own.
PUB DATE: January 13, 2026
Content warning: dementia, murder, violence, drug overdose
January 8, 2026
4 “love this series” stars!
FBI Agent Gardner Camden is back with his PAR (Patterns and Recognition) team. Their unit investigates cases that involve searching for patterns and repetitive data. Their numbers-driven, analytical minds and photographic memories find details and links that often get overlooked.
What starts as a case of an FBI informant found dead in a fraud and weapons stockpiling investigation, leads to a much larger case tracking down a serial killer.
There are several aspects that shine and stand out for me in this series. The lead FBI agent, Camden, is the narrator, who is a brilliant and highly entertaining main character. He is socially awkward, direct and quirky, yet so likeable. He is fully aware that he lacks social skills and it’s fascinating to read his inner thoughts on how he analyzes his own behaviour and social encounters. He has unique relationships with his family and his team. Another stand out aspect is the PAR team unit itself. Every team member brings a different layer of intrigue and backstory to the plot. They each have exceptional investigative abilities and analytical minds that aid the team as a whole. Their personalities and team comradery are a large piece of what pushes the plot forward and they each immensely add to an engaging and lasting connection with the reader. Lastly, the cases that are investigated are unique, captivating and clever, keeping the reader guessing until the end. The fascinating cases unfold in a fast-moving, twisty and enthralling way that keeps the reader on the edge of their seat from start to finish.
This is the second book in the series that could be read as a standalone, however, I highly recommend reading Book 1 first so you can get to know the amazing characters more deeply. I hope this series continues on!
Audio rating: 5 stars! The audio narrator is brilliant! The absolute perfect voice to fit Camden’s quirky personality. The audio narrator greatly enhanced my connection to the story.
Thank you to the publisher for my advanced listening copy! This publishes on Jan 13th.
FBI Agent Gardner Camden is back with his PAR (Patterns and Recognition) team. Their unit investigates cases that involve searching for patterns and repetitive data. Their numbers-driven, analytical minds and photographic memories find details and links that often get overlooked.
What starts as a case of an FBI informant found dead in a fraud and weapons stockpiling investigation, leads to a much larger case tracking down a serial killer.
There are several aspects that shine and stand out for me in this series. The lead FBI agent, Camden, is the narrator, who is a brilliant and highly entertaining main character. He is socially awkward, direct and quirky, yet so likeable. He is fully aware that he lacks social skills and it’s fascinating to read his inner thoughts on how he analyzes his own behaviour and social encounters. He has unique relationships with his family and his team. Another stand out aspect is the PAR team unit itself. Every team member brings a different layer of intrigue and backstory to the plot. They each have exceptional investigative abilities and analytical minds that aid the team as a whole. Their personalities and team comradery are a large piece of what pushes the plot forward and they each immensely add to an engaging and lasting connection with the reader. Lastly, the cases that are investigated are unique, captivating and clever, keeping the reader guessing until the end. The fascinating cases unfold in a fast-moving, twisty and enthralling way that keeps the reader on the edge of their seat from start to finish.
This is the second book in the series that could be read as a standalone, however, I highly recommend reading Book 1 first so you can get to know the amazing characters more deeply. I hope this series continues on!
Audio rating: 5 stars! The audio narrator is brilliant! The absolute perfect voice to fit Camden’s quirky personality. The audio narrator greatly enhanced my connection to the story.
Thank you to the publisher for my advanced listening copy! This publishes on Jan 13th.
December 8, 2025
Raising the PAR on FBI thrillers.
4.5 stars rounded up.
FBI Agent Gardner Camden and his team of incredibly talented "misfits" in the Patterns and Recognition (PAR) unit are back, this time juggling two very different - and possibly connected - investigations. When a confidential informant tied to a local militia is murdered, the team suspects something far more sinister is at play. An unidentified man captured on camera with the informant soon links to another FBI file: a string of murdered women buried across North Florida. As the PAR team races to untangle the connection between a possible serial killer and an emerging terrorist threat, the danger escalates.
"Inside Man" is a sharp, fast-paced follow-up to "Head Cases" that's grittier, higher-stakes, but every every bit as clever. I loved the first book, but this second installment in the series is even stronger. The stakes feel higher, the tension more palpable, and the plot more intricate. It’s a grittier, more emotionally charged read, though the team’s trademark quirks and intellectual brilliance occasionally take a back seat to the sheer pace of the casework. And while the murder investigation is the more compelling of the two threads, both deliver satisfying twists and John McMahon’s signature mix of intellect and heart.
While book two can be read as a standalone, there are a few spoilers for "Head Cases", so starting from book one is ideal. I received copies of both the ebook and the audiobook of "Inside Man" from the publisher for a truly immersive experience, and can highly recommend both. The audiobook, narrated by Will Damron, was a pleasure to listen to, with perfect pacing.
Smart, layered, and relentlessly engaging, "Inside Man" cements John McMahon as a must-read voice in modern FBI thrillers.
Many thanks to St. Martin’s Press | Minotaur Books and Macmillan Audio for providing me with ARCs of both the ebook and the audiobook via NetGalley in exchange for my honest review.
"Inside Man" is slated to be published on January 13, 2026.
4.5 stars rounded up.
FBI Agent Gardner Camden and his team of incredibly talented "misfits" in the Patterns and Recognition (PAR) unit are back, this time juggling two very different - and possibly connected - investigations. When a confidential informant tied to a local militia is murdered, the team suspects something far more sinister is at play. An unidentified man captured on camera with the informant soon links to another FBI file: a string of murdered women buried across North Florida. As the PAR team races to untangle the connection between a possible serial killer and an emerging terrorist threat, the danger escalates.
"Inside Man" is a sharp, fast-paced follow-up to "Head Cases" that's grittier, higher-stakes, but every every bit as clever. I loved the first book, but this second installment in the series is even stronger. The stakes feel higher, the tension more palpable, and the plot more intricate. It’s a grittier, more emotionally charged read, though the team’s trademark quirks and intellectual brilliance occasionally take a back seat to the sheer pace of the casework. And while the murder investigation is the more compelling of the two threads, both deliver satisfying twists and John McMahon’s signature mix of intellect and heart.
While book two can be read as a standalone, there are a few spoilers for "Head Cases", so starting from book one is ideal. I received copies of both the ebook and the audiobook of "Inside Man" from the publisher for a truly immersive experience, and can highly recommend both. The audiobook, narrated by Will Damron, was a pleasure to listen to, with perfect pacing.
Smart, layered, and relentlessly engaging, "Inside Man" cements John McMahon as a must-read voice in modern FBI thrillers.
Many thanks to St. Martin’s Press | Minotaur Books and Macmillan Audio for providing me with ARCs of both the ebook and the audiobook via NetGalley in exchange for my honest review.
"Inside Man" is slated to be published on January 13, 2026.
November 5, 2025
Inside Man is the second book in the Head Cases series, which follows a team of FBI agents in the Patterns and Recognition (PAR) unit, who solve complex cases that no one else can.
No sophomore slump for Mr. McMahon! I enjoyed Inside Man even more than I enjoyed the first book in the series, Head Cases. (FYI: Head Cases was the subject of a bidding war in Hollywood and is in development as a TV series at HBO Max!)
This time around, the PAR team (of four) is investigating the murder of a confidential informant, uncovering a connection to an unsolved series of murders in Florida, and a possible tie-in to another case, two thousand ghost guns. My only complaint about Inside Man was one of my pet peeves: Overuse of the word "hustling." I always think they're about to start disco dancing!
I absolutely love the relationship between Camden and his daughter, Camila, and the improving relationship between Camden and his former mother-in-law, Rosa. Hands down, though, my favorite part of the book pertained to magnesium powder. Fascinating! Also, very interesting were the author's notes at the end of the book. (Four spine surgeries in four months??😕) "Progress moves in only one direction" is the author's mantra.
All I can say is that I cannot WAIT for book three!!
HUGE thanks to #MinotaurBooks, for providing this book for review and consideration via #NetGalley. All opinions are my own. Inside Man has an expected publication date of January 13, 2026.
#JohnMcMahon #Crime #Mystery #Suspense #FBI #PatternsAndRecognition #Family
No sophomore slump for Mr. McMahon! I enjoyed Inside Man even more than I enjoyed the first book in the series, Head Cases. (FYI: Head Cases was the subject of a bidding war in Hollywood and is in development as a TV series at HBO Max!)
This time around, the PAR team (of four) is investigating the murder of a confidential informant, uncovering a connection to an unsolved series of murders in Florida, and a possible tie-in to another case, two thousand ghost guns. My only complaint about Inside Man was one of my pet peeves: Overuse of the word "hustling." I always think they're about to start disco dancing!
I absolutely love the relationship between Camden and his daughter, Camila, and the improving relationship between Camden and his former mother-in-law, Rosa. Hands down, though, my favorite part of the book pertained to magnesium powder. Fascinating! Also, very interesting were the author's notes at the end of the book. (Four spine surgeries in four months??😕) "Progress moves in only one direction" is the author's mantra.
All I can say is that I cannot WAIT for book three!!
HUGE thanks to #MinotaurBooks, for providing this book for review and consideration via #NetGalley. All opinions are my own. Inside Man has an expected publication date of January 13, 2026.
#JohnMcMahon #Crime #Mystery #Suspense #FBI #PatternsAndRecognition #Family
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January 18, 2026This was a great story. It features FBI Agent Gardner Camden and his PAR (Patterns and Recognition) team. They are a very interesting group of people. In this second installment the team is investigating a militia and illegal gun trafficking. When their informant is murdered they are drawn into a completely different unsolved case involving murdered women. The team is on a tight deadline to figure out who killed their informant and why as well as trying to determine how these two cases could possible be connected.
It is fascinating to be in Gardner's head and see how he processes information and tries to understand people. He is incredibly intelligent and logical, but struggles with basic interactions and works hard at understanding the emotion side of things. All of the characters have their own quirky personality traits and I really enjoy getting to know them all.
I read the first book in this series, Head Cases, and loved it. This second installment is just as good. Once again I am left looking forward to the next book in this series. It is really such a great series.
I was fortunate enough to have both the ebook and audiobook of this one. The writing is excellent and the narration by Will Damron is spot on. He suits Gardner's personality perfectly.
Thank you to NetGalley, St. Martin’s Press / Minotaur Books, and Macmillan Audio for providing me with complimentary electronic copies of this book. Opinions expressed in this review are completely my own.
It is fascinating to be in Gardner's head and see how he processes information and tries to understand people. He is incredibly intelligent and logical, but struggles with basic interactions and works hard at understanding the emotion side of things. All of the characters have their own quirky personality traits and I really enjoy getting to know them all.
I read the first book in this series, Head Cases, and loved it. This second installment is just as good. Once again I am left looking forward to the next book in this series. It is really such a great series.
I was fortunate enough to have both the ebook and audiobook of this one. The writing is excellent and the narration by Will Damron is spot on. He suits Gardner's personality perfectly.
Thank you to NetGalley, St. Martin’s Press / Minotaur Books, and Macmillan Audio for providing me with complimentary electronic copies of this book. Opinions expressed in this review are completely my own.
January 13, 2026
FIVE STAR ALERT!
⭐️⭐️⭐️⭐️⭐️
The Patterns and Recognition (PAR) unit of the FBI is back and this time they're diving into not ONE, but TWO cases simultaneously! One case involves the militia, a dead confidential informant (CI) and a stockpile of g*uns. When the team begins to look into who killed their CI, they stumble across another case involving a probable serial killer. Are the two cases connected? If so, how?
This starts off INTENSE! The action begins from chapter one and doesn't let up the entire time. Each case is complex with several moving pieces at any given moment. Gardner, the team leader, is neurodivergent and though he may think differently than most people, his uniqueness is NOT a flaw, it's a gift. He actively works at his social skills and interpersonal relationships which only serves to make him a beloved character for me. His relationships with his mother, daughter and one of his teammates (who may be something more), are a highlight and oftentimes funny, offering a respite from the seriousness of the investigations. John McMahon excels in writing endearing, complex and believable characters as well as detailed and layered criminal cases.
EDIT: Added 1/13/26
Huge confession: I had already read the book when the audiobook became available and I just had to read it again, because the story is that well-crafted and Will Damron is a phenomenal narrator. He embodies Gardner so perfectly, I could hear him in my mind while I physically read the book. Damron is a master at differing voices for every character along with emotional emphasis in all the right places and stunning modulation for scenes of excitement and danger. I highly recommend the audiobook for a fully immersive and cinematic experience!
This is the second book in the series and CAN be read as a stand alone, though I highly recommend reading both books in order because you won't want to miss a single minute with this team and there WILL be a few slight spoilers.
INSIDE MAN is fast paced, gripping and action packed with an edge-of-your seat climax and tons of heart. The PAR Unit series is one of my FAVORITES and it’s a MUST READ for crime fiction fans who love quirky characters, team dynamics, clever mysteries, and intense moments!
____
Expected publication date January 13, 2026
Massive thank you to Minotaur Books for my gifted copy. All opinions are my own.
⭐️⭐️⭐️⭐️⭐️
The Patterns and Recognition (PAR) unit of the FBI is back and this time they're diving into not ONE, but TWO cases simultaneously! One case involves the militia, a dead confidential informant (CI) and a stockpile of g*uns. When the team begins to look into who killed their CI, they stumble across another case involving a probable serial killer. Are the two cases connected? If so, how?
This starts off INTENSE! The action begins from chapter one and doesn't let up the entire time. Each case is complex with several moving pieces at any given moment. Gardner, the team leader, is neurodivergent and though he may think differently than most people, his uniqueness is NOT a flaw, it's a gift. He actively works at his social skills and interpersonal relationships which only serves to make him a beloved character for me. His relationships with his mother, daughter and one of his teammates (who may be something more), are a highlight and oftentimes funny, offering a respite from the seriousness of the investigations. John McMahon excels in writing endearing, complex and believable characters as well as detailed and layered criminal cases.
EDIT: Added 1/13/26
Huge confession: I had already read the book when the audiobook became available and I just had to read it again, because the story is that well-crafted and Will Damron is a phenomenal narrator. He embodies Gardner so perfectly, I could hear him in my mind while I physically read the book. Damron is a master at differing voices for every character along with emotional emphasis in all the right places and stunning modulation for scenes of excitement and danger. I highly recommend the audiobook for a fully immersive and cinematic experience!
This is the second book in the series and CAN be read as a stand alone, though I highly recommend reading both books in order because you won't want to miss a single minute with this team and there WILL be a few slight spoilers.
INSIDE MAN is fast paced, gripping and action packed with an edge-of-your seat climax and tons of heart. The PAR Unit series is one of my FAVORITES and it’s a MUST READ for crime fiction fans who love quirky characters, team dynamics, clever mysteries, and intense moments!
____
Expected publication date January 13, 2026
Massive thank you to Minotaur Books for my gifted copy. All opinions are my own.
December 8, 2025
Another great Camden Gardner book, along with his team of 'misfits.' It's amazing how the PAR team works together with all their strengths, and of course their intelligence. Two complicated cases, with places where they cross over, made for a great suspense!!
Thank you to Net Galley and St Martin's Press for allowing me to read this ARC in exchange for my honest review.
Thank you to Net Galley and St Martin's Press for allowing me to read this ARC in exchange for my honest review.
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December 7, 2025Kindled. Thank you for the arc, NetGalley.
To be clear: I adored Head Cases, the first book in this series.
A tempest in a teapot this book was. A whole lot of swirl and storm and to-ing and fro-ing. So much so that I got a bit tuckered out. I wondered how it was, given how large the state of Florida is, that the characters just happened to be a few miles from where they were suddenly needed. Like ALL THE TIME. And why did we need to know how tall everyone was?
Nitpicking much, Lisa?
Aw, I'm sorry, but my brain didn't quite adhere to this story as much as I'd wanted/expected. And, after all that investigating and digging and discussing; after all those miles logged, the ending/wrapping up/reveal was just so unsatisfying.
Darn.
I'm still a fan of McMahon's, though, and am about to start The Good Detective.
To be clear: I adored Head Cases, the first book in this series.
A tempest in a teapot this book was. A whole lot of swirl and storm and to-ing and fro-ing. So much so that I got a bit tuckered out. I wondered how it was, given how large the state of Florida is, that the characters just happened to be a few miles from where they were suddenly needed. Like ALL THE TIME. And why did we need to know how tall everyone was?
Nitpicking much, Lisa?
Aw, I'm sorry, but my brain didn't quite adhere to this story as much as I'd wanted/expected. And, after all that investigating and digging and discussing; after all those miles logged, the ending/wrapping up/reveal was just so unsatisfying.
Darn.
I'm still a fan of McMahon's, though, and am about to start The Good Detective.
January 3, 2026
Book 2 in the Head Cases series definitely did not disappoint! The team is back & hunting a ruthless serial k!ller after finding their confidential informant murd3red. As the case tightens, every move reveals how close the enemy really is and how high the stakes have become.
This case stressed them out bad! It seemed like the culprit stayed a step ahead of them the entire time & just when they thought it was over, another bomb dropped. I absolutely loved Cassie, her sassy comebacks were a highlight for me. Despite the seriousness of the case, she brought slight comic relief yet she was still a totally bad ahh.
The audiobook narration takes this story to another level. Will Damron always narrates very well to me & he perfectly captures the grit and intensity of this story! The pacing is excellent, pulling you deeper into the story with each chapter.
I enjoyed this one just as much as I loved book 1 and looking forward to reading more by John McMahon. Thank you NetGalley, St. Martin's Press for an eARC, and Macmillan Audio for an ALC.
Publication 🗓️ : 01.13.26
This case stressed them out bad! It seemed like the culprit stayed a step ahead of them the entire time & just when they thought it was over, another bomb dropped. I absolutely loved Cassie, her sassy comebacks were a highlight for me. Despite the seriousness of the case, she brought slight comic relief yet she was still a totally bad ahh.
The audiobook narration takes this story to another level. Will Damron always narrates very well to me & he perfectly captures the grit and intensity of this story! The pacing is excellent, pulling you deeper into the story with each chapter.
I enjoyed this one just as much as I loved book 1 and looking forward to reading more by John McMahon. Thank you NetGalley, St. Martin's Press for an eARC, and Macmillan Audio for an ALC.
Publication 🗓️ : 01.13.26
November 15, 2025
First and foremost, a large thank you to NetGalley, John McMahon, St. Martin's Press, and Minotaur Books for providing me with a copy of this publication, which allows me to provide you with an unbiased review.
Eager to return for this second novel in this collection by John McMahon, I gladly accepted this ARC to explore more about the Patterns and Recognition (PAR) Unit. FBI Agent Gardner Camden is back to test his skills against some of the most obscure puzzles crime has to offer. Agent Camden and the PAR Unit have an affinity for solving cases that no one else can crack, bringing their unique skills to the job. Working the case of a group stockpiling weapons, the confidential informant feeding PAR intel is killed. While it looks straightforward, it soon becomes clear that this militia group had nothing to do with it. Working every angle, a potential suspect is caught on camera with the CI. His identity is tied to another unsolved FBI case, which leaves Agent Camden and the unit juggling the pressure of two cases in opposite parts of the country. A number of women have turned up murdered and buried around northern Florida. hinting that a serial killer could be on the loose. None of this makes sense regarding the murdered CI, but no one is ready to toss in the towel just yet. A new CI is procured to help solve the gunrunning case, though things soon heat up anew and PAR is left scrambling as they seek to put all the pieces together. Two cases, no leads, and a group who thrive on puzzle solving. John McMahon impresses again with this piece!
The story works well as a thriller, as the reader remains wondering and flipping pages as they beg for answers. McMahon develops a great piece that keeps adding a strong foundation to this series. The narrative reminds the reader of the PAR Unit, pushing pieces together and providing strong pathways to guide things in a forward direction once again. With increased momentum, the reader is able to assemble things and keep the intensity, all while the story gets more twisted. I am eager to see how John McMahon will keep things going at this intensity as the series progresses.
Key characters provide some backstories as well as develop throughout the reading experience, never revealing too much at one time. This leaves the option open for more series
development, with Gardner Camden and others who surround him. I was eager to see him shed more light on his personal situation, as well as a professional advancement that could work well in future novels. Secondary characters complement the story well, allowing the reader to connect with many who play a role and develop affinities with ease.
There are constant plot twists in a thriller that leave things in an ongoing mystery. The reader can connect the dots, though they are sure to be surprised once again with McMahon's great writing style. Things are slowly exposed to keep the reader connected as truths surface in unexpected ways. I can hope that John McMahon will return with yet another novel, as there is much about him that remains opaque and in need of exploration.
Kudos, Mr. McMahon, for a wonderful follow-up piece.
Love/hate the review? An ever-growing collection of others appears at: http://pecheyponderings.wordpress.com/
Eager to return for this second novel in this collection by John McMahon, I gladly accepted this ARC to explore more about the Patterns and Recognition (PAR) Unit. FBI Agent Gardner Camden is back to test his skills against some of the most obscure puzzles crime has to offer. Agent Camden and the PAR Unit have an affinity for solving cases that no one else can crack, bringing their unique skills to the job. Working the case of a group stockpiling weapons, the confidential informant feeding PAR intel is killed. While it looks straightforward, it soon becomes clear that this militia group had nothing to do with it. Working every angle, a potential suspect is caught on camera with the CI. His identity is tied to another unsolved FBI case, which leaves Agent Camden and the unit juggling the pressure of two cases in opposite parts of the country. A number of women have turned up murdered and buried around northern Florida. hinting that a serial killer could be on the loose. None of this makes sense regarding the murdered CI, but no one is ready to toss in the towel just yet. A new CI is procured to help solve the gunrunning case, though things soon heat up anew and PAR is left scrambling as they seek to put all the pieces together. Two cases, no leads, and a group who thrive on puzzle solving. John McMahon impresses again with this piece!
The story works well as a thriller, as the reader remains wondering and flipping pages as they beg for answers. McMahon develops a great piece that keeps adding a strong foundation to this series. The narrative reminds the reader of the PAR Unit, pushing pieces together and providing strong pathways to guide things in a forward direction once again. With increased momentum, the reader is able to assemble things and keep the intensity, all while the story gets more twisted. I am eager to see how John McMahon will keep things going at this intensity as the series progresses.
Key characters provide some backstories as well as develop throughout the reading experience, never revealing too much at one time. This leaves the option open for more series
development, with Gardner Camden and others who surround him. I was eager to see him shed more light on his personal situation, as well as a professional advancement that could work well in future novels. Secondary characters complement the story well, allowing the reader to connect with many who play a role and develop affinities with ease.
There are constant plot twists in a thriller that leave things in an ongoing mystery. The reader can connect the dots, though they are sure to be surprised once again with McMahon's great writing style. Things are slowly exposed to keep the reader connected as truths surface in unexpected ways. I can hope that John McMahon will return with yet another novel, as there is much about him that remains opaque and in need of exploration.
Kudos, Mr. McMahon, for a wonderful follow-up piece.
Love/hate the review? An ever-growing collection of others appears at: http://pecheyponderings.wordpress.com/
December 12, 2025
John McMahon’s “Inside Man” is pure suspense magic. This is book two in the Head Cases series, and McMahon just keeps serving up characters I’d love to grab coffee with, or maybe just follow around while they solve crimes. At a safe distance!
Thanks to the author and Minotaur/Macmillan Audio for these gifted ARCs provided via NetGalley. All opinions are my own.
I started with the book, but I’m an audiobook addict, so I switched as soon as I got the chance. The narrator absolutely nails it, especially when it comes to Garner Camden. Picture a socially awkward FBI agent with a brain wired for puzzles and a rare, quirky sense of humor. On the page, he’s interesting, but in your ears, he’s unforgettable. I found myself grinning at his odd logic and rooting for his unique, wonderful brain. His mother is another memorable character!
The PAR Unit starts out chasing a militia with way too many weapons, but you know how thrillers love a twisty detour. Suddenly, we’re knee-deep in serial killer clues and whispers of something even bigger. McMahon keeps the tension cranked, but it’s Garner’s offbeat genius that steals the show.
Garner’s personality is captured perfectly. He’s officially on my list of fictional folks I’d invite to dinner. All his quirks and brainy brilliance come wrapped in so much charm, you can’t help but love him.
Read it or listen to it. “Inside Man” is a standout thriller. Garner Camden’s voice is worth hearing.
#InsideMan #JohnMcMahon #MinotaurBooks #MacmillanAudio #StMartinsPress
Book Series - Head Cases - Serial Killer - Cold Cases - NetGalley - CapCut - Canva - Audiobook Review
Thanks to the author and Minotaur/Macmillan Audio for these gifted ARCs provided via NetGalley. All opinions are my own.
I started with the book, but I’m an audiobook addict, so I switched as soon as I got the chance. The narrator absolutely nails it, especially when it comes to Garner Camden. Picture a socially awkward FBI agent with a brain wired for puzzles and a rare, quirky sense of humor. On the page, he’s interesting, but in your ears, he’s unforgettable. I found myself grinning at his odd logic and rooting for his unique, wonderful brain. His mother is another memorable character!
The PAR Unit starts out chasing a militia with way too many weapons, but you know how thrillers love a twisty detour. Suddenly, we’re knee-deep in serial killer clues and whispers of something even bigger. McMahon keeps the tension cranked, but it’s Garner’s offbeat genius that steals the show.
Garner’s personality is captured perfectly. He’s officially on my list of fictional folks I’d invite to dinner. All his quirks and brainy brilliance come wrapped in so much charm, you can’t help but love him.
Read it or listen to it. “Inside Man” is a standout thriller. Garner Camden’s voice is worth hearing.
#InsideMan #JohnMcMahon #MinotaurBooks #MacmillanAudio #StMartinsPress
Book Series - Head Cases - Serial Killer - Cold Cases - NetGalley - CapCut - Canva - Audiobook Review
January 15, 2026
FBI Agent Gardner Camden leads the Patterns and Recognition Unit, PAR, a small, eccentric team skilled at cracking cold cases by spotting overlooked patterns and details. Cassie, the brilliant mathematician; Shooter, a firearms expert; and Richie, the tech savvy rookie each bring something essential to the table.
What starts as an unemployment benefits fraud case quickly escalates into something far more dangerous. The scheme is tied to a militia group stockpiling weapons, and when PAR’s confidential informant is murdered, the team must dig for answers without tipping off the militia’s volatile leader. Their search uncovers chilling links to another investigation, one that suggests a serial killer may be operating in the shadows.
Gardner remains the heart of the story. His eidetic memory and knack for connecting stray details make him a phenomenal investigator, even as everyday social cues continue to trip him up. I loved seeing him balance his demanding job with his commitment to his young daughter. His mother in law remains a complicated but invaluable presence. There were developments with his mother since the events of the last book. Her sage advice continued to help Gardner navigate his social and professional life.
I adored Head Cases, and this follow up absolutely delivers! It’s a tightly plotted mystery that opens with a bang and never loses momentum, yet still finds space for the human side of Gardner and his team. I was hooked from page one and tore through this fast paced, high stakes thriller.
I alternately read and listened to Inside Man and recommend either version. Will Damron performed Gardner with a kind of matter-a-fact tone that fit with his character’s personality perfectly!
I voluntarily read/listened to an advanced copy courtesy of the publisher. These are my thoughts and opinions.
What starts as an unemployment benefits fraud case quickly escalates into something far more dangerous. The scheme is tied to a militia group stockpiling weapons, and when PAR’s confidential informant is murdered, the team must dig for answers without tipping off the militia’s volatile leader. Their search uncovers chilling links to another investigation, one that suggests a serial killer may be operating in the shadows.
Gardner remains the heart of the story. His eidetic memory and knack for connecting stray details make him a phenomenal investigator, even as everyday social cues continue to trip him up. I loved seeing him balance his demanding job with his commitment to his young daughter. His mother in law remains a complicated but invaluable presence. There were developments with his mother since the events of the last book. Her sage advice continued to help Gardner navigate his social and professional life.
I adored Head Cases, and this follow up absolutely delivers! It’s a tightly plotted mystery that opens with a bang and never loses momentum, yet still finds space for the human side of Gardner and his team. I was hooked from page one and tore through this fast paced, high stakes thriller.
I alternately read and listened to Inside Man and recommend either version. Will Damron performed Gardner with a kind of matter-a-fact tone that fit with his character’s personality perfectly!
I voluntarily read/listened to an advanced copy courtesy of the publisher. These are my thoughts and opinions.
January 14, 2026
4.5 stars. TWO CASES that may or may not be linked.. sounds good right!
I loved this fast-paced, unique, binge-read almost as much as Head Cases (1st book//5 stars) in this series. Inside Man is the 2nd series book that follows the FBI “PAR unit” doing what others cannot by using each of their own “unique” abilities when solving a case. Their next case has them hot on the trail of not only a serial killer, BUT also a militia that is stockpiling weapons. From the get-go this was an action-packed, edge of your seat wild ride that I couldn’t put down. So good. And my fave character, Gardner Camden//team lead, was on the tippy top of his game.. absolutely love his unique traits and genius thinking that makes this series so darn good.. and he’s also sporting some juicy history in his personal life.
And the audio.. just fantastic with Will Danton as narrator. Chefs kiss.. all the stars.
Do recommend McMahon’s “Head Cases” for your next (crime-thriller) series.. although both books can be read as a standalone. 🎧 Pub. 1/13/26
Much thanks to Macmillan Audio
via NetGalley! All opinion are my own.
I loved this fast-paced, unique, binge-read almost as much as Head Cases (1st book//5 stars) in this series. Inside Man is the 2nd series book that follows the FBI “PAR unit” doing what others cannot by using each of their own “unique” abilities when solving a case. Their next case has them hot on the trail of not only a serial killer, BUT also a militia that is stockpiling weapons. From the get-go this was an action-packed, edge of your seat wild ride that I couldn’t put down. So good. And my fave character, Gardner Camden//team lead, was on the tippy top of his game.. absolutely love his unique traits and genius thinking that makes this series so darn good.. and he’s also sporting some juicy history in his personal life.
And the audio.. just fantastic with Will Danton as narrator. Chefs kiss.. all the stars.
Do recommend McMahon’s “Head Cases” for your next (crime-thriller) series.. although both books can be read as a standalone. 🎧 Pub. 1/13/26
Much thanks to Macmillan Audio
via NetGalley! All opinion are my own.
December 31, 2025
4.25⭐️
Thank you to @macmillan.audio for the ALC and @minotaur_books for the galley! 🎧
This was a super fun follow up to Head Cases, and I really enjoyed it.. I think the domestic terrorism/murder mystery plot was even stronger than the first book, however it came at the expense of the characters’ development, which is what made the first book truly unique in the mystery / thriller category.
I will still definitely look forward to the next installment of the Patterns and Recognitions unit of the FBI and hope this is made into a tv series!
▶︎ •၊၊||၊|။||။|• 🎧 Will Damron captures Gardner Camden’s neurodivergent characteristics perfectly on audio.
Thank you to @macmillan.audio for the ALC and @minotaur_books for the galley! 🎧
This was a super fun follow up to Head Cases, and I really enjoyed it.. I think the domestic terrorism/murder mystery plot was even stronger than the first book, however it came at the expense of the characters’ development, which is what made the first book truly unique in the mystery / thriller category.
I will still definitely look forward to the next installment of the Patterns and Recognitions unit of the FBI and hope this is made into a tv series!
▶︎ •၊၊||၊|။||။|• 🎧 Will Damron captures Gardner Camden’s neurodivergent characteristics perfectly on audio.
December 27, 2025
The PAR is back with another case.. in their typical style, nothing is what it seems - This reminds me of Criminal Minds, specifically Matthew Gray Gubler with all the facts. The team is really good together. I really do like the evolution of Camden from the first book to this one.
Overall, loved! I’m grateful for an advanced copy!
Overall, loved! I’m grateful for an advanced copy!
December 9, 2025
The sequel to the brilliant Head Cases is finally here! I absolutely loved the first book and was so excited to get my hands on both the digital and audio versions of the follow up Inside Man. This series is so smart, so dark and so unpredictable, it is a joy to read.
Gardner Camden is now leading PAR - the puzzles and recognition team at the FBI. They have been incredibly successful in solving cases but this one will test them all. Whilst on the trail of a group of weapons smugglers, they find themselves hunting a serial killer . Their confidential informant has been murdered, and it by the gun guys! It is a dangerous case, one that will require everything the team has to put the puzzle pieces together.
The audiobook is narrated by the fabulous Will Damron, on of my favourite narrators. He is amazing at telling the story and keeping all the characters interesting and separated. I will listen to anything he reads.
Camden is such a great character, whip smart but struggles with emotions and personal relationships. His bond with his daughter is so strong and I love reading the chapters where they interact.
This is a fast paced adrenaline filled story that would make a great movie.i already can’t wait for the next book.
Thank you St Martin’s Press and Macmillan Audio for the advanced copies to read. Out on January 13th, a, must read for crime readers.
Gardner Camden is now leading PAR - the puzzles and recognition team at the FBI. They have been incredibly successful in solving cases but this one will test them all. Whilst on the trail of a group of weapons smugglers, they find themselves hunting a serial killer . Their confidential informant has been murdered, and it by the gun guys! It is a dangerous case, one that will require everything the team has to put the puzzle pieces together.
The audiobook is narrated by the fabulous Will Damron, on of my favourite narrators. He is amazing at telling the story and keeping all the characters interesting and separated. I will listen to anything he reads.
Camden is such a great character, whip smart but struggles with emotions and personal relationships. His bond with his daughter is so strong and I love reading the chapters where they interact.
This is a fast paced adrenaline filled story that would make a great movie.i already can’t wait for the next book.
Thank you St Martin’s Press and Macmillan Audio for the advanced copies to read. Out on January 13th, a, must read for crime readers.
December 6, 2025
Special thanks to NetGalley and the publisher for a free, electronic ARC of this novel received in exchange for an honest review.
Expected publication date: Jan. 13, 2026
“Inside Man” is the second novel in the “Head Cases” series by John McMahon. The PAR (Patterns and Recognition) Unit of the FBI investigates two connected cases in this new instalment, with missing guns possibly targeting the U.S government, and a long-cold case from Florida where women disappeared.
Gardner Cameron and his team are masters at puzzles, patterns and other mathematical mysteries, called in to assist when cases confound other units. What starts as the team investigating a militia group and disappearing weapons turns into an investigation into a group of missing women in Florida. Initially, there doesn’t seem to be any connection but Gardner and his team dedicate themselves to finding out the truth.
I was a huge fan of “Head Cases”, novel number one in this series. I loved the patterns and recognition aspect of the FBI unit and all of the quirky and unique personalities that made up the team. In “Inside Man”, the same characters are still there, with a few new faces and some interesting new facets of old relationships develop. This novel, however, had a lot of moving parts, with two cases for the price of one, and it was challenging to keep up with all of the people and lettered agencies that were involved.
Gardner is neurodivergent, which is obvious, as are most members of his team in one form or another, so he struggles to read a lot of social cues, which is sort of endearing, especially as he tries to figure out his relationship with his PAR partner, Cassie. His daughter, Camila, is now in his life more or less full-time and his mother, suffering from Alzheimer’s, has come out of her months-long coma. So, on top of all of the emotional stressors Cameron faces, he has the stress and pressure of solving the two cases at the risk of PAR being shut down. Needless to say, Gardner comes out on top. He’s brilliant and charming and he brings a Spencer Reid component to the plot.
McMahon’s writing is creative and the plot flows well, especially considering the simultaneous investigations. McMahon connects the two plots seamlessly, in a way that makes sense, and by the end I was left satisfied with the turn of events.
“Head Cases” should be read before “Inside Man” but it isn’t imperative, as both novels have different plots. Characters remain the same so some relationship details may be missed, and there are some aspects of the previous novel that were resolved in this one, but reading this as a stand-alone should still be enjoyable. I look forward to any future novels in this series, and to reading more about the awkward misfits that make up the PAR team.
Expected publication date: Jan. 13, 2026
“Inside Man” is the second novel in the “Head Cases” series by John McMahon. The PAR (Patterns and Recognition) Unit of the FBI investigates two connected cases in this new instalment, with missing guns possibly targeting the U.S government, and a long-cold case from Florida where women disappeared.
Gardner Cameron and his team are masters at puzzles, patterns and other mathematical mysteries, called in to assist when cases confound other units. What starts as the team investigating a militia group and disappearing weapons turns into an investigation into a group of missing women in Florida. Initially, there doesn’t seem to be any connection but Gardner and his team dedicate themselves to finding out the truth.
I was a huge fan of “Head Cases”, novel number one in this series. I loved the patterns and recognition aspect of the FBI unit and all of the quirky and unique personalities that made up the team. In “Inside Man”, the same characters are still there, with a few new faces and some interesting new facets of old relationships develop. This novel, however, had a lot of moving parts, with two cases for the price of one, and it was challenging to keep up with all of the people and lettered agencies that were involved.
Gardner is neurodivergent, which is obvious, as are most members of his team in one form or another, so he struggles to read a lot of social cues, which is sort of endearing, especially as he tries to figure out his relationship with his PAR partner, Cassie. His daughter, Camila, is now in his life more or less full-time and his mother, suffering from Alzheimer’s, has come out of her months-long coma. So, on top of all of the emotional stressors Cameron faces, he has the stress and pressure of solving the two cases at the risk of PAR being shut down. Needless to say, Gardner comes out on top. He’s brilliant and charming and he brings a Spencer Reid component to the plot.
McMahon’s writing is creative and the plot flows well, especially considering the simultaneous investigations. McMahon connects the two plots seamlessly, in a way that makes sense, and by the end I was left satisfied with the turn of events.
“Head Cases” should be read before “Inside Man” but it isn’t imperative, as both novels have different plots. Characters remain the same so some relationship details may be missed, and there are some aspects of the previous novel that were resolved in this one, but reading this as a stand-alone should still be enjoyable. I look forward to any future novels in this series, and to reading more about the awkward misfits that make up the PAR team.
January 16, 2026
I admit, this sounded like a good book, but I didn’t expect to love this story as much as I did - I ended up really enjoying it!!
This is a book that is fast paced right from the start. The team ends up trying to juggle two different cases and I loved the detail that went into this story and these characters. They are known as “the head cases” and are a little quirky but also so damn smart. The leader, Gardner approaches things and thinks a little differently than most people, but that is one thing that makes him so good at his job.
I liked that we also get to see him try and balance family life and work on understanding social queues too. As for the mystery/cases, I enjoyed following along as they tried to solve the cases.
I read this as a standalone and think I will be going back to read book one: Head Cases!
This is a book that is fast paced right from the start. The team ends up trying to juggle two different cases and I loved the detail that went into this story and these characters. They are known as “the head cases” and are a little quirky but also so damn smart. The leader, Gardner approaches things and thinks a little differently than most people, but that is one thing that makes him so good at his job.
I liked that we also get to see him try and balance family life and work on understanding social queues too. As for the mystery/cases, I enjoyed following along as they tried to solve the cases.
I read this as a standalone and think I will be going back to read book one: Head Cases!
September 14, 2025
upgraded to 2.5⭐️
the case in the second book did not keep me intrigued as the first one did. i was so sad bc i was so excited about the characters and unfortunately this one fell short.
there was a lot going on, and the first book was more “criminal minds” feel which i loved. this book felt more “bones” themed.
hopefully the next book is better☺️
thank you NetGalley & St. Martin’s Press for the digital ARC.
the case in the second book did not keep me intrigued as the first one did. i was so sad bc i was so excited about the characters and unfortunately this one fell short.
there was a lot going on, and the first book was more “criminal minds” feel which i loved. this book felt more “bones” themed.
hopefully the next book is better☺️
thank you NetGalley & St. Martin’s Press for the digital ARC.
January 1, 2026
This was nonstop action right from the start!!! 🙌
Fast paced and kept me turning the pages! While this definitely can be read as a standalone, I highly recommend starting with Head Cases first so you get to know the beginnings of the PAR team!! I honestly love these characters! If you enjoy fast-paced crime thrillers and Criminal Minds vibes, you should definitely check this out!! 👏
Thank you to partner Minotaur Books and NetGalley for the opportunity to read the eARC in exchange for my honest review! ❤️
Fast paced and kept me turning the pages! While this definitely can be read as a standalone, I highly recommend starting with Head Cases first so you get to know the beginnings of the PAR team!! I honestly love these characters! If you enjoy fast-paced crime thrillers and Criminal Minds vibes, you should definitely check this out!! 👏
Thank you to partner Minotaur Books and NetGalley for the opportunity to read the eARC in exchange for my honest review! ❤️
Review of advance copy received from Netgalley
Inside Man is a great sequel to Head Cases! Head Cases did a great job introducing the team individually and as a unit, while presenting an intriguing case. Inside Man can be read as a standalone - it has the same characters but a new exciting case.
The FBI "PAR" unit has a good mix of endearing characters. Gardner Camden, current team lead, has quite the history: he's responsible for his wife's incarceration. His daughter does not know about this betrayal; right now she adores her daddy and he does what he can to give her a stable life.
Richie is the rookie but he is determined to prove himself and is doing a great job so far. His responsibilities were increased in this book and his hunches helped the case progress.
Frank comes back to assist with oversight since the team has 2 cases to investigate that may be related. Despite his intentions in book 1, I like him and was glad for his return.
Big cases to solve and very little time to do it. This gives us a fast pace and plenty to ponder.
I enjoyed this book and recommend adding it to your TBR!
The FBI "PAR" unit has a good mix of endearing characters. Gardner Camden, current team lead, has quite the history: he's responsible for his wife's incarceration. His daughter does not know about this betrayal; right now she adores her daddy and he does what he can to give her a stable life.
Richie is the rookie but he is determined to prove himself and is doing a great job so far. His responsibilities were increased in this book and his hunches helped the case progress.
Frank comes back to assist with oversight since the team has 2 cases to investigate that may be related. Despite his intentions in book 1, I like him and was glad for his return.
Big cases to solve and very little time to do it. This gives us a fast pace and plenty to ponder.
I enjoyed this book and recommend adding it to your TBR!
January 18, 2026
I'm honestly more interested in the idea of this series. This was an okay rendering of PAR handling a two-case workload, one involving a serial killer and another involving black market guns. I was pretty bored.
January 19, 2026
Not one but two cases to solve in this sequel! Say less! Death of a CI, drugs, money, a serial killer, and possible terrorist plot? It’s got it all! And we learn more about FBI Agent Gardner Camden and his family in the sweetest science fair project way. Thanks to NetGalley and Minotaur / Macmillan for advanced copies for a honest review .
September 5, 2025
Review: This one was just as good as the first, I absolutely loved it. I love Gardner's characters and how he tries his best to be the best agent, parent, friend, person he can be. I loved the way the story wove around and how the pieces fell into place. I'll read any and all books in this series.
Synopsis: In this sequel to McMahon's electrifying series debut, Head Cases, Gardner Camden and the PAR team return to investigate potentially connected cases.
FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve.
PAR’s latest case involves a militia group stockpiling weapons. When their confidential informant in the case is killed, it quickly becomes clear that the militia did not kill him.
As the squad looks into the evidence surrounding his murder, an unidentified man is caught on camera with their informant. This mystery man’s picture is connected to another case at the FBI, an unsolved series of murdered women, buried in the ground in north Florida. Could they have uncovered a serial killer? And if so, what is his connection to their C.I.?
As PAR juggles an investigation into both the dead women and the militia, they enroll a new informant, only to find the case escalating in dangerous ways. How will PAR handle a case that increasingly looks like a terrorist plot? And in the serial case, with no puzzles or witnesses, and few leads, how will a group set up to decode riddles be successful?
Synopsis: In this sequel to McMahon's electrifying series debut, Head Cases, Gardner Camden and the PAR team return to investigate potentially connected cases.
FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve.
PAR’s latest case involves a militia group stockpiling weapons. When their confidential informant in the case is killed, it quickly becomes clear that the militia did not kill him.
As the squad looks into the evidence surrounding his murder, an unidentified man is caught on camera with their informant. This mystery man’s picture is connected to another case at the FBI, an unsolved series of murdered women, buried in the ground in north Florida. Could they have uncovered a serial killer? And if so, what is his connection to their C.I.?
As PAR juggles an investigation into both the dead women and the militia, they enroll a new informant, only to find the case escalating in dangerous ways. How will PAR handle a case that increasingly looks like a terrorist plot? And in the serial case, with no puzzles or witnesses, and few leads, how will a group set up to decode riddles be successful?
December 19, 2025
A long time fan of Criminal Minds, I was immediately hooked by Head Cases when it was published last year. I found Gardner Camden and the entire PAR unit to be brilliant puzzle solvers. This unusually talented team returns in INSIDE MAN, the second book in the Head Cases series and it’s wonderful to be reunited with this group of uniquely talented agents.
This time Camden is in charge of PAR as the unit is investigating a case involving a string of ATM thefts. Their work quickly points to something far more sinister and that leads them to a string of unsolved disappearances of young women in Florida. Camden and his team of cerebral agents see connections linking the two cases and it’s a race against time to catch the bad guys.
John McMahon does an outstanding job laying out the backstory of Camden and the PAR, so it’s possible to read this as a stand-alone, but the experience is so much better starting with the first book.
INSIDE MAN is a fast paced and intricate cat-and-mouse game, but it is easy to follow as the reader is privy to Camden’s thought process and inner monologue. The police procedural elements of this book are extremely well written, but I’m particularly invested in the relationships between the characters. They are adept at capitalizing on the unique talents of each member of the team and begin to form a cohesive unit the longer they work together.
Will Damron reprises his narration in this second book and continues to be brilliant as he takes us into Camden’s inner thoughts. This is a pulse quickening audio production that enhances the story. Highly recommend consuming this book via audio.
Thank you to NetGalley, St. Martin’s Press, Minotaur Books, and Macmillan Audio for the advance copies. All opinions are my own.
This time Camden is in charge of PAR as the unit is investigating a case involving a string of ATM thefts. Their work quickly points to something far more sinister and that leads them to a string of unsolved disappearances of young women in Florida. Camden and his team of cerebral agents see connections linking the two cases and it’s a race against time to catch the bad guys.
John McMahon does an outstanding job laying out the backstory of Camden and the PAR, so it’s possible to read this as a stand-alone, but the experience is so much better starting with the first book.
INSIDE MAN is a fast paced and intricate cat-and-mouse game, but it is easy to follow as the reader is privy to Camden’s thought process and inner monologue. The police procedural elements of this book are extremely well written, but I’m particularly invested in the relationships between the characters. They are adept at capitalizing on the unique talents of each member of the team and begin to form a cohesive unit the longer they work together.
Will Damron reprises his narration in this second book and continues to be brilliant as he takes us into Camden’s inner thoughts. This is a pulse quickening audio production that enhances the story. Highly recommend consuming this book via audio.
Thank you to NetGalley, St. Martin’s Press, Minotaur Books, and Macmillan Audio for the advance copies. All opinions are my own.
January 16, 2026
In this sequel to Head Cases, we return to Gardner Camden and the rest of the Patterns and Recognitions team at the FBI - a small group of FBI agents who may be slight oddballs, but put their brilliant minds to use solving crimes in a different way. In this book, the death of the team’s confidential informant leads to them simultaneously pursuing two different mysteries at the same time - a militia group stockpiling weapons, and a potential serial killer.
And wow, great book - multiple great mysteries, great thrilling action - I seriously could not put the book down and stayed up too late finishing it. I also love the characters - especially the way we get to see the world through Gardner’s unusual viewpoint - he’s seemingly on the spectrum but while he may outwardly be devoid of emotion, he really has so much love in his heart for his family and fellow agents.
This book series has apparently been optioned for a tv show by HBOMax, and it will definitely make a great show so I hope they make it. Though it may be too scary for me to watch if they do. 😂 I’ll also eagerly read any other further books in this series, as well as checking out John McMahon’s other books, past and future.
Thanks to NetGalley and the publisher for my e-ARC (came out this week so available now); all opinions are my own.
And wow, great book - multiple great mysteries, great thrilling action - I seriously could not put the book down and stayed up too late finishing it. I also love the characters - especially the way we get to see the world through Gardner’s unusual viewpoint - he’s seemingly on the spectrum but while he may outwardly be devoid of emotion, he really has so much love in his heart for his family and fellow agents.
This book series has apparently been optioned for a tv show by HBOMax, and it will definitely make a great show so I hope they make it. Though it may be too scary for me to watch if they do. 😂 I’ll also eagerly read any other further books in this series, as well as checking out John McMahon’s other books, past and future.
Thanks to NetGalley and the publisher for my e-ARC (came out this week so available now); all opinions are my own.
Review of advance copy received from Netgalley
Gardner Camden and his colleagues at PAR are back back for another thrill ride of both action and mental gymnastics taking the mystery trope of the brilliant detective to the nth degree. Within the FBI, the misfits and masterminds solve the unsolvable, breaking out of the boxes as they go. A 3-month investigation into gunrunners that may have militia implications has just gotten their confidential informant killed. While attempting to keep that case from imploding, they discover leads pointing to a serial killer operating in South Florida. Both cases may be linked somehow. Meanwhile, I am rapidly turning pages trying to follow the team's though processes. Entertaining as hell. Camden's a great character, especially as he learns to process social cues using his intellect. If you haven't read Head Case yet, why not? Do it! In the first book, you get more about all the personalities on the team which could deepen your enjoyment of this one. Still, this firecracker of a mystery stands on its own. My first five star read of 2026!Thanks to St. Martin's Press and netgalley for the complimentary copy. All opinions are my own..
January 15, 2026
3.5 rounding up. I love this crew of misfits and geniuses and every case with them is equal parts fun and intriguing. I enjoyed this one but it felt a bit disconnected. There are two cases and they have a connection but it’s so tenuous that I did t really buy it. I almost wish it was just two completely different cases so I wasn’t scratching my head over the connections and the various geographies.
PAR lands a case involving illegal guns and they find their CI murdered but they aren’t sure by whom. As they rush to find his killer while preventing the sale and use of the guns the team has to grapple with their own personal issues and internal politics.
Gardner is the brains and the heart in this one. His neurodivergence is a huge asset and while he has trouble expressing himself, he clearly cares deeply about everyone in his life. He’s a pleasure to hang with in this series. There’s a lot of splitting off and way too many threads to follow but Gardner remains a place of calm for most of it.
PAR lands a case involving illegal guns and they find their CI murdered but they aren’t sure by whom. As they rush to find his killer while preventing the sale and use of the guns the team has to grapple with their own personal issues and internal politics.
Gardner is the brains and the heart in this one. His neurodivergence is a huge asset and while he has trouble expressing himself, he clearly cares deeply about everyone in his life. He’s a pleasure to hang with in this series. There’s a lot of splitting off and way too many threads to follow but Gardner remains a place of calm for most of it.
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