Lee San (Lee Min Ho), a man with a mysterious past, excels in martial arts. YO (Chung Hon Leung) is an intelligent investigator who worked for Interpol. As fate would have it, the duo ends up joining a group of bounty hunters including the smart and beautiful Cat (Tang Yan) and other members. Their first mission is to find out the serial bomber whose target is Hotel A. However, during their mission, Cat and the other members are kidnapped by Tommy (JeremyJones Xu), the son of the ex-Chairman of Hotel A; Tommy shockingly confesses to be the mastermind behind the bombing!