Action thriller about a loose-cannon cop on the trail of three drug-dealing brothers. For years, Detective Sergeant Ma Jun (Donnie Yen) has been working on a case involving three Vietnamese brothers - Archer (Lui Leung-Wai), Tony (Collin Chou) and Tiger (Xing Yu). Ma has planted a mole, his partner Wilson (Louis Koo), to infiltrate the gang and Wilson has managed to gain the trio's trust and respect. But during a police sting operation, Tony and Tiger discover Wilson's identity, with Archer being arrested by police. The two brothers vow to save Archer by destroying evidence and killing all police officials and witnesses involved in the case.