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.

Sicilian baron, Mimì Galluzzo, will be able to enjoy the legacy of his deceased father-in-law on two conditions: that his wife accepts the will and that there is a compromising document to be delivered to the mafia. While, however, the precious "dossier" is, in reality, in the hands of an avid widow, Donna Maria, willing to sell it only if Mimi marries her. Rosalba, obsessed with the absence of a child, suddenly goes mad or pretends 'go crazy. Recommended by Donna Maria, of whom he became the lover Don Mimì tries, with the help of his friend Langatta, undertaker, and a nurse in the clinic in which Rosalba was hospitalized, to get rid of his wife. Instead, he finds himself without having reached his goal, involved in an obscure series of crimes that will make him lose his mind.

Set in Sicily, this violent crime drama tells the tale of an Italian cop who heads to a small island town to look into the death of a construction supplier. Once there he is shocked by the influence the Mafia has over the people and even himself.