Ba Reum keeps a close eye on Kang Duk Soo's murder investigation. Bong Yi on the other hand, thinks Moo Chi was the killer of Kang and keeps her mouth shut even when she's being speculated as a suspect.

Ko Nam, a bright and insightful kid finds out about a cat killer around his neighbourhood. One day, he promises to share his personal investigation with Bong Yi but unexpectedly goes through an accident. Ba Reum and Moo Chi dig deeper to find out who would've done such a heinous act to a little kid.