A gym teacher and his female student look for her missing friend. But as they investigate, they find that her disappearance is a part of a larger conspiracy.
Kim Ji-yong leads a double life as a Korean National Police University student by day and the Vigilante by night, personally punishing criminals who evade the law. He is surrounded by people who all possess different ulterior motives.
Jang-soo is a judo instructor who is indifferent to everyone but his daughter. One day he realizes he can see Tae-jin, a ghost who used to be a devoted police officer. Tae-jin asks Jang-soo to help solve the case that took his life away from him.
