After "Mark il poliziotto" obtained a great commercial success, it generated two sequels, "Mark il poliziotto spara per primo" and "Mark colpisce ancora".
Police believe that a respectable industrialist is actually the head of drug smuggling ring in Milan.
Mark Terzi goes to Genoa to take on the case of a serial killer who calls himself "The Sphinx".
A murderous drug dealer breaks his partner out of police custody. An undercover cop is assigned to track down the two killers and bring them in.
