Original: 이토록 친밀한 배신자
A criminal profiler begins questioning everything he’s ever believed about seeking justice after learning his daughter is linked to a murder case.
Tae-su's tenacity makes him South Korea's top profiler. But his work gets in the way of being a parent, especially when his daughter is a suspect.
Tae-su wants to trust his daughter, but all evidence points to Ha-bin. He draws suspicion from Officer Dae-hong, who begins investigating the case.
New revelations emerge as Tae-su investigates Ha-bin's alibi, while Eo-jin begins to question Tae-su's involvement in the case.
After Tae-su submits a keychain as evidence, the police discover a link to another case. Yeong-min is brought in for questioning once more.
Tae-su receives a shocking call as secrets begin to tumble out. Agitation and suspicion over the unfolding investigation begin to mount.
While Dae-hong is disappointed with the changes in Tae-su, Eo-jin learns about her colleague’s past. Ha-bin reaches a breaking point with Yeong-min.
Another murder forces Tae-su to question his daughter as the evidence points to her involvement. Jun-tae turns himself in.
A mysterious envelope arrives at the police station. Ducheol blackmails Taesoo using Habin. Habin learns the secret behind Jisu's death, while Eojin firmly suspects Habin as the killer.
The violent crimes unit identifies Habin as a suspect. Taesoo realizes there's no escape this time. He desperately tries to block the investigation, but soon faces a shocking truth through the evidence seized from Habin.
The true killer is revealed, but the motive behind the murder remains unclear. Habin refuses to let go of the intent to kill, leaving Taesoo with deep guilt. Can this father-daughter duo live a normal life from now on?
