To put an end to the inhuman adoption and refund system, Ah-hyun and the kids set out on a daring mission to confront the head of the evil organization. With fierce determination and a carefully crafted plan, they infiltrate the organization's bunker to strike from within. But once inside, Ah-hyun uncovers a devastating truth behind the system.

Framed for murder, Ah-hyun and the kids turn to the only adult they trust, Detective Choi. Meanwhile, the unexpected and unwanted return of of Seok-su, the adoptive son who was believed to be dead, throws Kwon Kang-man into a crisis, leading him to seek ways to put an end to the adoption on his own.