An evil spirit that changes faces infiltrates one family placing one brother in danger while the other tries to save him.

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.

Unlike Gi-hoon, who is happy running a noodle shop with his mother in their hometown, Ji-eun distances herself from her family due to her ambition to succeed as an idol singer. The siblings, who have been hurting each other more than showing love, find their conflict deepening with the news of their mother's Alzheimer's, whom they thought would stay young forever.