Killadi Police (2014)

When a spate of eerie murders erupts across Hong Kong two troublemaking cops are assigned to the case. Young maverick Wang and grizzled vet Huang who is fed up with his reckless younger partner always landing them in hot water. Reaching a dead end after discovering all the victims were former boyfriends of aspiring starlet Liu, the detectives must play a deadly game. One of them must go undercover as Liu's lover to lure the killer out.