After a family tragedy, Chuck Wilson hopes to start a new life in Ashland Falls with his wife Maria and little sister Isabelle, but he quickly discovers that the town has a dark secret.
Yujeong, who works as a night shift nurse at a general hospital's cardiology department, is now told that her 12th-grade younger sister, Kijeong, has been arrested by the police as a suspect in an infant abandonment case. Only then does Yujeong start to make desperate efforts to rescue her sister.