Season 1

Hyung Bin who is a detective asks his girlfriend, Ha Eun to marry him. But she refuses because of her heart disease. Meanwhile, another dead body has been found. Some crazy woman rushes into the crim scene and picks up …

Ha Eun teaches kids at the church. By chance, Ji Chul takes her class and he ends up falling in love with Ha Eun. One day, Ji Chul sees an abused child who used to be his friend dead. Ha Eun collapses from her heart dis…

Ha Eun collapses after she witnesses a murder scene. And Hyung Bin finds out that it was Ji Chul who brought Ha Eun to the hospital. Hyung Bin protects Ha Eun day and night after the incident, and Ji Chul always watches…

Ha Eun visits Ji Chul before the trial and asks him if he killed accidentally. But Ji Chul answers he would've done the same even if he goes back in time. Ji Chul is put in a psych ward but escapes. Ha Eun heads to the …

Jong Bum runs into Sa Bin at the University and he finds out that she had a heart implant when she was young. Sa Bin hears rumors about Jong Bum from students that he's actually a psychopath and he has killed someone. S…

Jong Bum goes home but his father and brother don't seem to like him at all. The mummy found from Donggang River turns into skeletons in a day. Su Hyuk keeps feeling pain in his eye and Jong Bum's hand keeps twitching. …

Su Hyuk tries to forge the evidence of Donggang River mummy so Byun Sung Hoon can be sentenced to life. Jong Bum visits a woman's house to do the errands for her and she asks him to have a drink with her. Sa Bin and her…

Su Hyuk finds out that it was Jong Bum who was with the victim of a copycat murder case. But Su Hyuk feels pain in the heart as he follows Jong Bum to the exhibition and sees him with Sa Bin. The criminal Byun Sung Hoon…

Su Hyuk saves Sa Bin from a terrible car accident. Sa Bin's heart starts to pound for Su Hyuk. Su Hyuk tells Jong Bum's father that Jong Bum is the prime suspect of a murder case. Jong Bum decides to leave his family.

Sa Bin posts the restored image of a mummy from Donggang River. Su Hyuk finds out that Sa Bin posted the image and gets furious. Ji Chul picks up the notebook that Sa Bin dropped and reads about Gong Ji Chul. Su Hyuk ma…

After the remains of a buried baby are found, Jong Bum and Su Hyuk face each other as a prime suspect and a prosecutor. Jang Hye Mi, the writer of "Secrets of A Murderer," says that Gong Ji Chul was never a psychopath. …

It turns out that the remains were identified as Lim Hwa Young's baby. Sa Bin realizes Jong Bum's relationship with his little brother and sympathizes with him. Sa Bin and Su Hyuk visit “Old Future,” the secondhand book…

Su Hyuk lost his father who believed in humanity in the past. After his death, Su Hyuk has been fighting against beast-like criminals. Jong Bum’s feelings for Sa Bin grow bigger. But he finds out that Sa Bin has feeling…

Sa Bin sees the painting of Cain and Abel and has a hunch that something will happen with Jong Bum and his little brother, so she follows him to the charity gala. Sa Bin almost drowns and as she's close to death, she re…

Su Hyuk investigates what happened on the day Jong Woo almost drowned and finds out Jong Bum was at the lake before the incident. Meanwhile, Jong Bum shows up where Sa Bin is using the tracking application. Su Hyuk visi…

Sa Bin struggles with her feelings for Su Hyuk. Jong Bum decides to get rid of Su Hyuk for Sa Bin and himself. Chief Prosecutor Chun warns Su Hyuk to leave Jong Bum alone, but Su Hyuk makes up his mind to go against him…

Sa Bin gets transferred to the hospital after she was stabbed by a thug. Su Hyuk finds out that it was Jong Bum who incited to murder Su Hyuk. Sa Bin notices that there is a tracking app on her phone and she assumes tha…

Jong Bum takes a picture of Detective Ju being attacked by someone. And he meets and talks with the attacker. Su Hyuk says goodbye to his fiancee and confesses his feelings for Sa Bin. Su Hyuk discovers that Jong Bum’s …

Su Hyuk sees Jong Bum on the camera which was installed at the place where Detective Ju was attacked. So Su Hyuk believes Jong Bum attacked Detective Ju. Jong Bum notices his house was robbed by someone and realizes tha…

Jae Yi tells Su Hyuk that Jong Bum has been stalking Sa Bin. And Su Hyuk is convinced that Jong Bum attacked Detective Ju after hearing the recording file from Detective Ju’s phone. Jong Bum invites Sang Ah, telling her…

Tae Ha takes Jong Bum to the hospital. Jong Bum’s mother falls into despair as the doctor tells her a bullet is in Jong Bum’s head and that his brain might be damaged. There has been a rumor that Jong Bum went to Americ…

Finally, the remains from Donggang River are restored with a hologram. But as Su Hyuk sees the hologram, he collapses with unknown memories and pain. After he opens his eyes, it seems like Su Hyuk has become someone els…

Feeling confused, Hyung Bin heads to Old Future. He asks the owner where Ha Eun was buried. After Jong Bum opened his eyes, he introduced himself as Gong Ji Chul in the test he had at the hospital. A male remains are fo…

Ji Chul tells Hyung Bin that the real killer is Gong In Woo. Hyung Bin finds the killer’s paintings from 30 years ago. Ji Chul visits Hye Mi and threatens to bring Gong In Woo. Hyung Bin finally gets to where Ha Eun was…

Gong Ji Chul and Gong In Woo finally meet. From their conversation, Hyung Bin realizes that it was Gong In Woo who killed all those women in the past. Meanwhile, the face of the death-row convict who was found by the se…

Sang Ah is taken to the police as a suspect of the Yellow Murder Case. Hye Mi presses Suk Tae to let Sang Ah to be released. Ji Chul threatens Hye Mi with the identification card of her stepfather. But it seems like Ji …

Sang Ah goes to trial and Detective Ju testifies that it was Sang Ah who stabbed him. But Hye Mi denies all charges as her lawyer. Seok Tae keeps trying to stop Su Hyuk from digging into Ji Chul’s case, but Su Hyuk is d…

Su Hyuk realizes someone broke into his house and took files related to his past cases. Sa Bin receives a message about his father and hurries to the hospital. In Woo tries to kill Sa Bin, but luckily Jong Bum comes on …

Seok Tae gets into trouble after Gong In Woo was arrested for the Yellow Umbrella Murder. As the crisis deepens, Hye Mi presses Tae Ha to take care of Su Hyuk. So Tae Ha decides to put an end to all. Sa Bin wakes at the…

The broadcast about Gong In Woo goes viral and the photos of Gong In Woo and his victims are sent to Su Hyuk by someone. Sa Bin feels lost in between the feelings for Su Hyuk and Jong Bum. In Sang Ah’s trial, the photo …

Su Hyuk submits his resignation and visits Tae Ha to apologize. He suggests for the retrial for Tae Ha’s brother. Sa Bin tells Jong Bum that it was Seok Tae who killed Ji Chul in the past. Donggang Mummy is identified a…

Sa Bin collapses after days of crying. Jong Bum can’t stand watching her sad so he makes up his mind to save her. Sa Bin gives the ring back to Su Hyuk saying her heart now belongs to Jong Bum. The time is running out f…