A mad killer is loose in Venice's catacombs. He attacks the beautiful women, releasing them into the underworld, kill them and then stop them and add them to his "collection".

In 1943, four Italian Alpini escape back to Italy after their company was decimated in Croatia by Yugoslav partisans. One of the four, Paolo, is seriously wounded and must undergo a leg amputation. The young man, embittered by his mutilation and the end of his soccer career, enlists in the fascist Brigate Nere. Once a member of the Brigate Nere, Paolo turns to evil and captures his former comrades, who must defeat him.