When security cameras catch members of an elite police tactical unit savagely beating a suspect in a dark alley, internal affairs investigators start digging to uncover the identities of the offending cops. With the police fighting each other and the victimized suspect now missing, one debt-ridden officer takes matters into his own hands. Simon Yam, Maggi Siu and Suet Lam star in this sequel to the hit 2003 film PTU.