Tough cop Ken Li (Cheng) is at the top of his game, but he's going to need some help to solve a grisly crime that the offender, a respected police officer, doesn't even remember committing. He seeks out Jack Lai (Lai), a former psychologist now in disgrace and behind bars, who has an uncanny ability to bend people to his will. Making an uneasy truce, this unconventional pair set out on a mission to find the man responsible, a master of hypnotism who will stop at nothing to get his revenge!
Un malfrat est grièvement blessé à la tête durant un interrogatoire qui tourne mal. Conduit à l'hôpital, il y refuse les soins d'urgence et tente de gagner du temps pour que ses complices viennent le récupérer. L'inspecteur responsable de la bavure n'est pas dupe, mais décide de jouer le jeu dans l'optique de coincer la totalité du gang...