Kang San-hyuk, a director at a package distribution company plagued by financial irregularities, suffers a delusion that his right arm is on fire while being treated at the hospital where Jung Young-jae, a surgeon, works.
San-hyuk is attacked while investigating a suspicious business deal involving Miryeong forest. Young-jae is reassigned to work in the Miryeong forest area after shocking a patient in order to stop him from strangling his son.
After they meet in Miryeong forest, San-hyuk drives Young-Jae to the hospital where she will be working, which she finds cold, dusty, and underequipped. While he is in the forest, he again suffers a delusion that his right arm is on fire.
Oh Bo-mi, a forest officer, rushes San-hyuk to the hospital while he is suffering from a delusion that is right arm is on fire. Young-jae treats him. Choi Chang, a rescue officer, protects Young-jae from danger during a rescue drill.
San-hyuk joins the rescue team after passing a civil service exam, but he finds the training hard and must move closer to the team's base in order to his job. Young-jae orders new equipment so that she can serve the hospital's patients.
San-hyuk becomes Young-jae's new neighbor, which they both discover while they are half-dressed. San-hyuk offends Young-jae by claiming they plan to marry while they attend an event at the hospital where she hopes to resume working.
Young-jae tries to drum up patients for the hospital by making house calls in Miryeong village but receives a hostile reception. San-hyuk brings Young-jae a teddy bear and lunch. His behavior offends her, but she appreciates the food.
Bo-mi pursues a suspicious vehicle in the forest. The driver flees, abandons his vehicle and falls off a cliff. An accident occurs when the rescue team tries to save him. Young-jae has to perform emergency surgery. She has a panic attack.
After coming to the aid of Young-jae following her panic attack, San-hyuk returns to work expecting to be treated like a hero, only to find himself being reprimanded for not following instructions. San-hyuk's arrogance irritates Young-jae.
Young-jae is appointed to be the doctor for the rescue team. When San-hyuk questions a professor about the results of a study on noise, an attempt is made on his life. When San-hyuk appears to be in danger, Young-jae rushes to his aid.
Young-jae and San-hyuk go for a walk in the Miryeong woods, during which he observes her enthusiasm for nature. The hospital director sends a group of patients to Miryeong hospital, which reminds Young-jae that her work is helping people.
When San-hyuk and Chang are brought to the hospital to be treated for injuries incurred on a rescue mission, they vie for Young-jae's attention. San-hyuk and Young-jae have a testy conversation about relationships that ends in a kiss.
Jung Byung-hyuk explains the tragedy that led him to adopt Young-jae. San-hyuk meets Young-jae's father under awkward circumstances. San-hyuk learns that the people interfering with his plans for Miryeong forest are from the Taesung group.
San-hyuk investigates why the rescue team's base is not in the optimal location so that he can find a way to move the base. San-hyuk suffers pain in his right arm after seeing a name beneath a drawing in the forest. Young-jae comforts him.
Young-jae and San-hyuk go for a bicycle ride in the forest. Dr. Park surprises Young-jae by suddenly taking an interest in his work. Chang discovers a reason to be suspicious of San-hyuk. San-hyuk discovers that somebody is spying on him.
Young-jae learns the villagers have been drinking contaminated mountain water. She is caught in a forest fire while searching for its source. San-hyuk rescues her but becomes disoriented as he recalls the fire that destroyed the village.
San-hyuk realizes he caused the fire that destroyed Miryeong village. Young-jae investigates the source of the contaminated water, while Bo-mi investigates the source of the fire. San-hyuk tells Young-jae his goals come before her.
Bong Dae-yong asks Young-jae whether San-hyuk is suffering from post-traumatic stress disorder. San-hyuk learns that a member of Taesung group built the rescue team's base. San-hyuk and Young-jae travel to Manila for different reasons.
San-hyuk tries to arrange a secret business deal. To keep Young-jae away from her ex-boyfriend, San-hyuk brings her to a business meeting. When his business partner falls ill, San-hyuk assists Young-jae in treating his business partner.
Young-jae learns that San-hyuk's mother abandoned him at a bus station as a child. When Young-jae tells San-hyuk their relationship will not work since she cannot trust him, he tells her that his chief goal in life is to be with her.
San-hyuk and Young-jae revel in the newfound happiness their relationship brings. San-hyuk's business maneuvers anger his rival in the Taesung group. Young-jae is asked to travel to the hospital in Seoul. San-hyuk meets with Choi Jung-mok.
San-hyuk's rivals gather information on him. Bo-mi pursues her arson investigation. Young-jae receives a report indicating that arsenic is in the mountain water. Jo Kwang-Pil frightens Young-jae by visiting her in the hospital after hours.
San-hyuk rescues Young-jae when she falls into a pool. She tells him how she nearly drowned when her parents committed suicide. Young-jae learns that Dr. Park suspected that contaminated water was harming residents of Miryeong village.
Young-jae shows Bo-mi evidence that the village water is contaminated. Jo Kwang-pil has Park Hyung-soo abducted and assaulted. San-hyuk and Hyung-soo outmaneuver Kwang-pil, angering Kwon Joo-han. Joo-han decides to target Young-jae.
Jung Byung-hyuk retires. Choi Jung-mok kicks his son Chang out for dating Oh Bo-mi. Chang moves in with San-hyuk. Team leader Bong Dae-yong seeks Young-jae's help with his alcohol problem. San-hyuk has a flashback while rescuing a child.
Young-jae learns that there are high arsenic levels in the mountain's soil, which she tells San-hyuk. Young-jae is arrested for kidnapping a patient she is transferring to a hospital. San-hyuk discovers an illegal mine on the mountain.
Young-jae is jailed on false charges. San-hyuk learns that Miryeong mountain contains rare earth metals. He works to get the charges against Young-jae dropped. Young-jae is blocked from alerting the public to the heavy metal contamination.
Young-jae confronts San-hyuk about his plan to mine Miryeong mountain for rare-earth metals, which would poison the villagers. San-hyuk recalls that Choi Jung-Mok set the fire that killed his sister San-Yoo and burned Miryeong village.
Kang San-hyuk joins the Taesung group in order to find out the source of the heavy metals contaminating Miryeong mountain. Young-jae, Dr. Park and Nurse Kim investigate whether village residents have been poisoned by the mountain water.
Jung Young-jae, Dr. Park and Nurse Kim collect evidence that the residents of Miryeong village have been poisoned. Kang San-hyuk exposes illegal mining practices by the Taesung group. Young-jae and San-hyuk are trapped in an arson attack.
Kang San-hyuk recuperates in a hospital under an alias provided by Jung Young-jae. Young-jae stores evidence that the village residents have arsenic poisoning. Kwon Joo-han kidnaps San-hyuk to stop San-hyuk from exposing his malfeasance.
Kwon Joo-han is tried for his crimes based on evidence that Kang San-hyuk helped collect. Jung Young-jae's adoptive father shows her evidence that her biological parents tried to save her life. Young-jae overcomes her fear of water.
