On the first day of new year, police detective Yeon-woo is urgently dispatched to town of Seonyang to investigate a murder case, along with her reunited partner Sang-hyuk. The victim of the gruesome murder is Dr. Cha Yo-han, the respected director of Eden Medical Hospital. As Yeon-woo and Sang-hyuk question the staff members of the hospital, they realize that though the people cooperate to the investigation, their answers are empty, not giving the police any helpful information. 

Meanwhile, Do-jin, a lawyer working in Seoul receives an anonymous note telling him to defend Yoo Min-hee who is arrested by Seonyang Police department, convicted for murder. On the envelope of the note, “Gangwon-do Seonyang-gun Eden Medical Hospital” is written. Seonyang is Do-jin’s hometown from where he ran away 15 years ago after a tragic accident. Though he has chosen to forget the memory of the accident, he had no choice to follow the anonymous order, as the note threatened to reveal the truth about the past if he did not follow it. However, when he arrives at Seonyang Police department, he is greeted by a shocking news. The victim of the case was his father, Cha Yo-han.

Yeon-woo and Sang-hyuk is suspicious of Do-jin, who claims to be appointed as Yoo Min-hee’s lawyer even before she was taken in. Grasping the situation, Do-jin soon realizes that the real target of the murder is him. Fifteen years ago, there was a group of friends in Seonyang High School. Centering Do-jin, who was the son of the respected doctor, Min-jae, Seo-hyun, Ihan, and Yoon-seok gathered. The five teenagers were good friends sticking up for each other. All the people in Seonyang thought highly of his father, but Do-jin was always afraid of him. He knew from early on that his father was wearing a façade. Then one day, Min-jae tells a strange rumor about Eden Medical Hospital, that people have heard screams coming out of Seonyang hospital at dawn. Despite Min-jae’s 
continuous request to go and take a look, Do-jin does not seem interested, but when Min-jae mentions that it could be a way to find out his father’s weakness, Do-jin agrees to go. Few days later, the five teenagers break into the closed ward of Seonyang Medical Hospital, which leads to an unexpected discovery.