Detective Jang’s missing notebook mysteriously appears at Lee Hyun’s home. Following the clues in the notebook, Ji-an and Lee Hyun arrive at the original home of Lee Joon-yeong. They discover a casket with the bones of what may be Joon-yeong’s mother. Park Joo-ah, one of the family caregivers, comes forward and relates Joon-yeong’s childhood and the death of everyone else living there. Detective Ji-an’s stalking skills are put to use resolving key issues Lee Hyun is categorizing in his head, and he realizes that every time he visited Korea, he was given a gift box that contained clues left by his brother. Joo Yeong-jae, a student, is murdered, and the adoptive parents' actions are questioned.
지안과 현은 22년 전 일가족 실종사건 현장에서 준영의 충격적 과거와 마주한다. 한편 현은 주영재 사건을 추적하던 중 누군가에게 소포를 받게 되는데..
