Detective Han (JUNG Woo-sung) who for years has been secretly doing dirty work for the corrupt mayor Park Sungbae (HWANG Jung-min) is now pressured by a ruthless prosecutor Kim Cha-in (KWAK Do-won) to cooperate in an investigation against the mayor. Feeling trapped Han persuades his young partner Sunmo (JU Ji-hoon) to take over his work for the mayor but things start to get tangled in unpredictable ways. As things are getting worse only the most evil survives in this dog-eat-dog world.