Undercover cop Cheung returns to his police academy for training. He has to be discharged earlier. Once outside he is brutally murdered by the 'Gang of Four.' Three years later, his pupils n... Read allUndercover cop Cheung returns to his police academy for training. He has to be discharged earlier. Once outside he is brutally murdered by the 'Gang of Four.' Three years later, his pupils now police officers, track down the gang and avenge the death of their tutor.Undercover cop Cheung returns to his police academy for training. He has to be discharged earlier. Once outside he is brutally murdered by the 'Gang of Four.' Three years later, his pupils now police officers, track down the gang and avenge the death of their tutor.