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.