Detective Squad Chief Choi is set for a promotion and he has a party with his co-workers to celebrate, but, on the way home, a crime occurs and he accidentally commits murder. Because of his promotion, he decides to cover up the crime. The next morning, TV news reveals a body is hanging from a crane at a construction site. Choi is shocked because the body hanging is the person he killed last night. He takes charge of the murder investigation. Later, the police station receives a mysterious phone call.