Plot

A madman who believes he's a doctor comes to the town where his crazy father was killed, and soon begins murdering people and becoming infatuated with a teenage girl who has a heart condition.

The psychopathic son of a mass-murdering doctor, escapes from his mental institution to seek revenge on the town where his father was caught. The giggling doctor kills his victims with a surgical theme. His goal being to give one of the townfolk a heart transplant.—Rob Hartill

The nightmare begins decades earlier when the original Dr. Rendell, a respected physician in the small town of Moorehigh, secretly murders his patients in twisted medical experiments. When the townspeople discover his crimes, they storm his house and kill him, but not before his young son Evan witnesses the brutal scene while hiding inside his father's body cavity - a grotesque hiding place that scars him for life. Years later, the adult Evan Rendell has spent his time in a mental institution perfecting his surgical skills and plotting revenge against those responsible for his father's death. When he finally escapes, he returns to Moorehigh with a collection of makeshift medical instruments and an insatiable desire to continue his father's work. Adopting the moniker "Dr. Giggles" due to his distinctive, unnerving laugh, he begins systematically tracking down his targets. Jennifer Campbell, a teenager with a serious heart condition, becomes Rendell's primary obsession. Her medical vulnerability reminds him of his own childhood trauma, and he becomes convinced that by "operating" on her, he can somehow heal his own psychological wounds. Jennifer lives with her father and struggles with the limitations her heart condition places on her life, making her an ideal victim in Rendell's twisted medical philosophy. Dr. Giggles begins his killing spree by targeting various townspeople with elaborate, medically-themed murders. He uses syringes filled with cleaning fluid, performs impromptu "surgery" with rusty instruments, and dispatches victims with creative applications of medical knowledge turned deadly. Each kill is accompanied by his signature giggle and medical puns that reveal his complete disconnection from reality. As the body count rises, the town gradually realizes they're dealing with more than random violence. The connection to the old Dr. Rendell case emerges when survivors from the original incident recognize the killer's methods. Jennifer's father, along with other townspeople, begin to understand that they're facing the son of the doctor they killed decades ago, now returned to exact his revenge. Jennifer finds herself increasingly targeted as Dr. Giggles stalks her through various locations around town. Her heart condition becomes both a vulnerability and, paradoxically, a source of strength as she refuses to let her medical limitations define her response to the threat. The killer's obsession with her intensifies as he begins to see her as the perfect patient for his ultimate surgical procedure. The climax builds toward a final confrontation where Dr. Giggles captures Jennifer and prepares to perform his masterpiece operation. He has constructed an elaborate surgical theater where he plans to "cure" her heart condition through his demented medical procedures. Jennifer must use her wits and determination to survive while her friends and the remaining townspeople race to find her before the mad doctor can complete his deadly work. In the final showdown, Jennifer turns the tables on her captor by using his own medical obsessions against him. The confrontation reveals the full extent of Rendell's psychological damage while providing Jennifer with the opportunity to overcome both her stalker and her own medical fears. The resolution addresses the cycle of violence that began with the original Dr. Rendell while establishing Jennifer as a survivor who has conquered her physical limitations through extraordinary circumstances. The film concludes with the apparent defeat of Dr. Giggles, though true to slasher convention, hints remain that his medical practice might not be permanently closed. Jennifer emerges transformed by her ordeal, having faced down both a literal monster and her own mortality, while Moorehigh attempts to heal from both its recent trauma and the sins of its past.