A bounty hunter is someone who gets paid to do someone's bidding. One must have a specific expertise in order to qualify. Lee San (Lee Min Ho), who has a mysterious past is an expert martial artist. Yo (Chung Hon Leung) is a former INTERPOL agent turned investigator. Together they opened a bodyguard service and accepted a job to protect Sam, a reporter from Incheon, South Korea. As fate would have it, the duo ended up joining a group of bounty hunters that include the smart and beautiful Cat (Tang Yan), a genius hacker Swan (Karena Ng) and Bobo (Louis Fan) who has incredible strength. Their first mission was to find the serial bomber whose target is Hotel A. The group tracked the bomber from Bangkok, Thailand back to South Korea and split up to look into the bombing of Hotel A in Jeju. While Lee San and Yo excelled, Swan, Cat and Bobo were kidnapped by Tommy (JeremyJones Xu), the son of the ex-Chairman of the hotel. Tommy confessed to be the mastermind behind the bombing. What was his motive? Will the bounty hunters complete their mission?