After being disowned, Ah Hyun lives in hiding with three kids, training every day to protect themselves.

Ah Hyun and the kids find out the truth behind the "refund" system and decide to take revenge.

Hints from Han Cheol Soo help Ah Hyun get closer to the brutal truth, and Se Hee starts on a new project.

Ah Hyun and the kids are hunting down the monster. Inside the bunker, a horrifying truth awaits Ah Hyun.

The kids do everything they can to save Ah Hyun, while Se Hee's ambition shows no signs of stopping.

Accused of murder, Ah Hyun and the kids ask Detective Choi for help. Their next target is Kwon Kang Man.