An ex-Vietnam vet is forced to become a hit-man and gets caught in the middle of a conspiracy.
Bruno Fioretti, known as "Mandrake", is an inveterate gambler who never misses a day at the horse racing track in Rome. He is doubly unlucky: he bets too much on one horse, and his wife is sleeping with his best friend because Mandrake is always at the track. Penniless and cuckolded, Mandrake decides to make one last bet.
A concentration camp survivor discovers her former torturer and lover working as a porter at a hotel in postwar Vienna. When the couple attempt to re-create their sadomasochistic relationship, his former SS comrades begin to stalk them.