Giovanni Bertone a former colonel, is a fraudster who extorts money from the families of the Nazi-Fascist prisoners. He promises them their freedom. Discovered by Colonel Muller he is offered a pact: to save his life, he must go to Milan with a false identity to discover the members belonging to the Resistance.
Italian fugitives from German war camps unite to form "Lupo", a partisan brigade which uses their knowledge of the countryside to wage their own personal war on the Germans.