A woman's life is turned upside-down when a dangerous man gets a hold of her lost cell phone and uses it to track her every move.

On her father’s birthday, Jihee visits her childhood home with her husband and child, feeling anxious. Having married against her family’s wishes, she shrinks under her father’s coldness until tensions finally erupt.

The story of a serial killer, Yeong-hoon, who murdered 11 people, offering a special interview with Seon-joo, a veteran reporter who is desperate for a scoop.