Criminal profiler Kang Tae-ju is pulled out of retirement by a chilling summons: an imprisoned serial killer has been linked to additional unsolved deaths through DNA evidence, but he insists that Tae-ju join the investigation, believing that Tae-ju can prove his innocence. Tae-ju is brought back into a world he thought he’d left behind 33 years earlier, forcing him to face ambitious prosecutor Cha Si-yeong, with whom he shares a difficult past, in pursuit of the truth. But as with many cold cases, the truth isn’t as straightforward as it seems, and Tae-ju might be more involved than even he knows. Can Tae-ju finally close the chapter on the ''Scarecrow'' murders for good, or will a new twist upend his life?

Criminal profiler Kang Tae-ju is pulled out of retirement by a chilling summons: an imprisoned serial killer has been linked to additional unsolved deaths through DNA evidence, but he insists that Tae-ju join the investigation, believing that Tae-ju can prove his innocence. Tae-ju is brought back into a world he thought he’d left behind 33 years earlier, forcing him to face ambitious prosecutor Cha Si-yeong, with whom he shares a difficult past, in pursuit of the truth. But as with many cold cases, the truth isn’t as straightforward as it seems, and Tae-ju might be more involved than even he knows. Can Tae-ju finally close the chapter on the ''Scarecrow'' murders for good, or will a new twist upend his life?