Doctor John

There is an emergency patient who needs treatment immediately at Chungil Penitentiary. The warden calls 911, but Yo Han secretly appears and treats the patient. Si Young plans a trip to Madagascar, but she is short of money. At that moment, Jeong Nam calls Si Young and offers her a part-time job.

Si Young wants to go back to the hospital again, but she thinks she doesn't deserve to save patients. She thinks that never wearing a doctor's gown again is a punishment for herself. At the penitentiary, Inmate 5353 visits Si Young because of a rash, and Yo Han tells her that Inmate 5353 needs to go to an outside hospital urgently.

Yo Han and Si Young think that Inmate 5353 is suffering from Fabry disease. Si Young tells Yoo Joon that the patient has Fabry disease, but Yoo Joon tells her there are only 100 people in the whole country who have the disease. Meanwhile, Si Young gets to know why Yo Han was imprisoned.

Yo Han is sure that Jung Bo’s is suffering from Fabry disease, and he suggests to Si Young that she should run an enzyme test for the last time. Si Young goes to Kyungwon Hospital again, but Jung Bo is nowhere to be found all of a sudden. Meanwhile, Tae Kyung announces Si Young's comeback to the hospital.

A mixed martial arts fighter Joo Hyung Woo gets injured during his match. Yo Han tells Hyung Woo that he needs to be treated right away if he doesn’t want to lose his sight. Many doctors in Seoul Hanse Medical Center oppose Yo Han’s reinstatement, but he comes back to the hospital thanks to Tae Kyung.

Tae Kyung warns Yo Han not to cause any trouble. Yo Han wants Si Young to stay out of Hyung Woo’s case because he doesn’t want her to get into trouble too. Si Young encounters Eun Jeong, and Eun Jeong tells Si Young what happened to Yo Han three years ago.

Hyung Woo’s wife wants to respect Hyung Woo’s will, but his father wants to save him. Yo Han keeps trying to find out the name of Hyung Woo’s disease. Meanwhile, Hyung Woo’s condition gets worse again, and Yo Han wants to treat him once again.

Jeong Nam asks Yo Han to take good care of Si Young, and Yo Han tells him that Si Young is doing great. Si Young asks Yo Han if he doesn’t have any regrets about his decision three years ago. She is afraid of the fact that a patient’s life is in her hands, and Yo Han tells Si Young that a patient needs a doctor just like her.

Mi Rae tells Si Young that she wants Yi Soo to stay alive even if he is bedridden. Doctors in Seoul Hanse Medical Center start questioning about Yi Soo’s life-prolonging treatment, and Tae Kyung seems to be confused. Si Young wants to find the restaurant where she and Yi Soo had dinner for the last time, and Yo Han helps her to find the restaurant.

The patient who insists he has CRPS comes to see Yo Han. At the same time, a student whose arm is badly hurt comes to the Pain Management Center, and Yo Han thinks he has CIPA. Si Young and Mi Rae carry out Seung Won’s examination together, and Mi Rae thinks Si Young’s excessive empathy disturbs an accurate diagnosis.

Seok Ki tells Yo Han that only society’s forgiveness can erase Yo Han’s criminal record. No matter what Seok Ki says to him, the only thing that matters to Yo Han is what kind of doctor he is to his patients. Gi Seok feels no pain because of CIPA, but he can feel pain all of a sudden. However, CIPA is an incurable disease, so Yo Han is confused.

Gi Seok doesn’t want to get surgery because he doesn’t want to go back to his old days. Yo Han shows Gi Seok something and persuades him to get surgery. The Pain Management Center’s members have a team dinner at Yoo Joon’s mother’s restaurant. During the dinner, Mi Rae asks Yo Han if euthanasia was a final prescription for the patient.

Yo Han tells Si Young to keep his condition a secret. Si Young worries about Yo Han after she knew about his disease. Yo Han calls in sick, and Si Young goes to his house because she worries about his condition. However, Yo Han tells her not to over react. Meanwhile, Seok Ki visits Tae Kyung.

Deok Kyu comes to the Pain Management Center to receive treatment, and the other patients who took the same bus with him seem to have fever.

Yo Han wants to go inside the center, but Seok tells him no one can enter the center under any circumstances. Yo Han goes inside the center despite Seok’s opposition, and Si Young worries about him since the virus can be dangerous to him. Meanwhile, Yo Han keeps trying to diagnose the suspected patient’s disease

Heo Jun tries to cure his patient’s phantom limb pain. Si Young worries about Yo Han, so she checks his BP and pulse to see if his condition is fine. Si Young wants to understand Yo Han, but Yo Han tells her that she can’t understand him. Meanwhile, Seok Ki goes to Death Talk’s gathering, and he gets to meet one person who is critically ill.

After Si Young’s confession to Yo Han, Yo Han doesn’t mention anything about it, and Si Young wonders why he doesn’t say anything. Tae Kyung tells Yo Han to act and speak carefully since the dispute about the life prolonging treatment of Chairman Kang will happen soon.

Yo Han collapses all of a sudden, and Si Young finds him at that time. Si Young calls Yoo Joon for help, and they take Yo Han to another hospital. Si Young is worried about him, but Yo Han tells her that he doesn’t need her help. Meanwhile, Seok Ki becomes suspicious of Zinmu Rijund.

Yo Han suddenly feels dizzy during the presentation. At that time, Si Young comes up to the stage and continues the presentation. Yo Han admits that he needs her help, and he goes to his doctor to have a comprehensive check-up. Meanwhile, Seok Ki goes to the exhibition and finds a suspicious painting.

Si Young and other doctors in the Pain Management Center want to grant Ri Hye’s wish, and Ri Hye wants to see her son. Tae Kyung prepares for the ethics commission and the board meeting to elect a new chairman. Meanwhile, the results of Yo Han’s checkup come out, but the results are not good.

Jung Rok and Seok Ki are suspicious of Yo Han, but the doctors claim that Yo Han is not the culprit. Seok Ki starts interrogating Yo Han, and Yo Han feels dizzy during the investigation. Ri Hye’s sister decides to agree with Ri Hye’s DNR, and Ri Hye has a heart attack again.

Yo Han meets Ri Hye’s son at the hospital's rooftop. Yo Han tries to save Ri Hye’s life, and Ri Hye finally regains her consciousness. Yo Han tells Seok Ki that the role of a doctor is to determine what is most beneficial to patients. Meanwhile, Tae Kyung decides to convene a disciplinary committee to punish Yo Han.

Yo Han and Si Young go to Jung Bo’s cafe, and Jung Bo is pleased to see them in a while. Hyun Sook, a member of Death Talks, is reported missing, and Jung Rok shows Seok Ki a video of Hyun Sook that was sent to her husband. Meanwhile, Yo Han and Si Young do grocery shopping together.

Yo Han gets to see Seok Ki at the Emergency Medical Center, and he takes a look at Seok Ki’s medical record. Yo Han comes back to the hospital, and the other doctors in the Pain Management Center welcome him back. Meanwhile, Eun Jeong hears about Yo Han’s secret from Seung Hyun.

Seok Ki asks Yo Han how he can understand his patient’s pain when he is a CIPA patient who can’t feel any pain. Gi Seok opens his eyes, and he can answer to Yo Han’s question by blinking his eyes. Meanwhile, Eun Jeong exposes Yo Han’s secret by writing it on the hospital’s bulletin board.

Yo Han wants to treat Gi Seok, but the disciplinary committee decides to exclude him from all medical duties. To find out the reason why Gi Seok is sick, Yo Han goes to the warehouse where Gi Seok was bullied by other students. Meanwhile, Eun Jeong gets to know that Seok Ki is sick.

Tae Kyung thinks that it is not right to fire Yo Han. Ri Hye gets a strange text from Death Talks. Won Gil meets Yo Han and tells him about the Cherubim. However, Yo Han gets furious about the idea of the Cherubim, and he calls Seok Ki to report Won Gil.

It was Chan Seok, the sales manager of Zinmu Rijund, who injected the Cherubim to the members of Death Talks. Myung Oh and Chan Seok leave Korea after Won Gil’s death. The patients who were treated by Yo Han come to the disciplinary committee to oppose the dismissal of Yo Han.

Cha Yo Han is deeply shocked by Gi Seok's death. After administering treatment to Son Seok Ki whose condition had worsened, Cha Yo Han decides to leave his life at Seoul Hanse Medical Hospital as well as Si Young. However, Si Young tries to change his mind and tells him to be honest about his feelings.

Chairman Kang Yi Soo dies. Tae Kyung, Si Young, and Mi Rae mourn his death. Mi Rae decides to move back in with Si Young. Later, when she finds out that Yo Han was about to board a plane, she rushes to tell Si Young. Meanwhile, with the chairman's passing, Joo Kyung asks Tae Kyung to consider taking over his position.

Si Young can’t reach Yo Han, and she is worried about him. However, Yo Han doesn’t contact her for three years. After the three years, Yo Han finally comes back to the hospital and meets Si Young, but he doesn’t explain what happened to him for the past three years.

Yo Han suggests Si Young that she should do a brainwave test on the patient. Si Young asks Yo Han why he didn’t tell her that he was sick, and Yo Han apologizes to her. Yoo Joon tells Si Young that Yo Han kept watching Si Young for a year, and Yo Han and Si Young finally confirm their love.