Detective JO ? who commits all sorts of wrongs and crosses all sorts of lines for money ? gets Detective KANG as his new partner, the National Police Academy's top graduate. Following procedures by the book when it comes to police work, KANG argues with JO at every turn. Then one day, Soo-won visits KANG and appeals to him to help her with an anonymous and suspicious character that's been threatening her. Both detectives will stop at noting to impress her and to pursue the case with uncanny methods.