Plot
A couple with a sick child cross the border from France to Italy, but their car is involved in a collision and crashes, decapitating the driver and leaving the other passengers dead. The police commissioner (Enrico Marciani) finds that the child had been dead for some time before the crash and that the corpse had been filled with tubes of heroin and demands that the perpetrators be found. Angered by the increased activity of the police, the 'boss of bosses' (Gennarino Pappagalli) calls a meeting of mafia leaders, where outrage is expressed at the use of a child in the smuggling operation. Don Ricuzzo Cantimo (Fausto Tozzi), an American mafiosa now based in Sicily, is blamed and Don Cascemi (Vittorio Sanipoli) is chosen to bring him under control.
When Cascemi leaves the meeting, he is followed by a mysterious man wearing a large gold ring and driving a VW Beetle. When he arrives home he is attacked by three of Cantimo's henchmen, who kidnap him, drive to a deserted clifftop where, after giving him a warning, they plan to abandon him. Suddenly, a whistled tune drifts across the evening air, and then all the henchmen are shot dead, the bullets piercing the centre of their foreheads.
It is revealed that Cascemi's rescuer is the driver of the Beetle, Tony Aniante (Henry Silva), who has been brought to Sicily from America by Cascemi to help with the problematic Cantimo. He tells Tony that the problems originate in the feud between Cantimo and Don Turi Scannapieco and his family, centred on the town of Colle Pietra. Tony drives to the town, and rents a room, but not before being recognised by Cantimo's principal henchman (Giancarlo Del Duca).
Two of Cantimo's men are driving a cart loaded with cherries, including a consignment of drugs, when they are attacked and murdered by two Scannapieco men, who are in turn killed by Tony. He drives the cart to the house owned by Don Turi Scannapieco (Mario Landi), Although suspicious that his men have not brought the cart themselves, Scannapieco welcomes Tony and pays him for his trouble, introducing him to his grandson Zino (Alfredo Pea), who had been crippled following an attack by Cantimo that killed his father.
That evening, in a bar in Colle Pietra, Tony is accosted by four of Cantimo's henchmen, but beats them up. The next day Tony talks to a priest and it is revealed that he had grown up locally and has personal matters to settle in the town. Their conversation is interrupted by an 'invitation' to visit Cantimo, and Tony is driven to his villa. While waiting outside, Tony looks into a barn and sees a beautiful woman in a frilly pink dress massaging fresh milk into the skin of her thighs - they instantly connect but Tony is called away before they speak.
Don Cantimo revals that he knows exactly what Tony's involvement with the cherry heist was, and he asks Tony to arrange for the return of the drug consignment. Cantimo will provide men to kidnap Zino to use as a bargaining chip, while Tony will negotiate a swap with the drugs. He also introduces Tony to his American wife Margie (Barbara Bouchet), who is the blonde from the barn. It emerges that Margie is an alcoholic, and that Cantimo can only make love to her if she tells him about sex she has had with previous partners.
Cantimo's men kidnap Zino as planned, but then the mysterious whistling is heard again, and Tony kills them both, subsequently crushing their corpses with a handily placed steamroller. He returns Zino to his grandfather, and Scannapieco agrees to return Cantimo's drugs. Tony has dinner with Cantimo and Margie, during which she eats a banana in a suggestive manner, then a storm prevents him from going home, so he agrees to stay the night. When Tony goes to the kitchen for some water in the middle of the night, he finds Margie there. She demands sex, telling him that she will pretend that he tried to rape her if he refuses. When Tony insults her, she is happy to admit that she was a cheap prostitute when she met Cantimo. Tony has violent sex with her, forcing her face into a bloody pig carcas hanging from the ceiling.
When Tony wakes the next day he finds that Cantimo's men have staged an early morning attack on Scannapieco's villa, killing many men including his son Carlo. Carlo's brother Alfio (Pietro Torrisi) accuses Tony of betraying his family and attacks him with a hay fork, but Tony knocks him out. As he leaves, Tony tells Don Turi that he has a plan that will help gain revenge for the death of his son.
When Cantimo leaves to meet another drug shipment, Margie accosts Tony again and. when he rejects her, she threatens to tell her husband that Tony has betrayed the family. In a rage he slaps her and, when she runs into a barn, he follows her and beats her with his belt, eventually hitting her repeatedly in the face with the buckle. Aroused by reducing her face to a bloody pulp, he has sex with her in the barn.
Meanwhile Cantimo's gang is ambushed by Scannapieco's men, and a gun battle ensues. Alfio is killed and a desperate Don Turi challenges Cantimo to a duel to settle their differences, but is mortally wounded. When Cantimo gets home he finds the injured Margie and in a fury, orders his men to find and kill Tony. They catch him and beat him severely, throwing him into a quarry and leaving him for dead, but he has survived and is soon found by Zino, who gives Tony his dead grandfather's gun.
A severely injured Tony arrives alone at Cantimo's villa, and faces off against Cantimo and his henchmen. Cantimo tells him that Margie has killed herself, and that he will soon be joining her in hell but, at the last minute, a crowd of gunmen appear on the walls of the compound and massacre Cantimo's men. Although Cantimo himself is not killed immediately, Tony shoots him dead.
A delighted Don Cascemi pays Tony for a job well done, but Tony has no plans to leave Sicily and reveals that he knows that it was Cascemi who had planned the original smuggling operation in order to justify the elimination of Cantimo. Cascemi grabs Tony's gun, admits his guilt, and shoots Tony in the face - but the gun is unloaded. Tony now reveals his real reason for coming back to Colle Pietra - his parents had been murdered by Coscemi years earlier and he has returned to avenge their deaths.
Cascemi calls for help, his henchmen arrive and multiple gunshots are heard. But it is Cascemi who falls dead, and Tony who is driven away in a convoy of cars in a position of honour. Clearly, the mafia bosses already knew the truth, and Tony has been chosen to take over Don Cascemi's empire.
