Four criminals execute a daring robbery of a vehicle carrying company wages. However, their escape takes a turn for the worse when their getaway car is damaged, resulting in the death of one of their own. The surviving thieves—Doc (Maurice Poli), Blade (Aldo Caponi), and Thirty-Two (Luigi Montefiori)—are compelled to flee on foot into an underground parking garage while being pursued by the police. In a desperate move, they take hostages and, after a mishap that leads to the accidental death of one, the police pull back when they see another hostage, Maria (Lea Lander), in peril, allowing the criminals a chance to escape in her vehicle.
Understanding that the authorities will swiftly broadcast a description of their new getaway car, Doc decides they must hijack another vehicle. The new driver, Riccardo (Riccardo Cucciolla), pleads with them, explaining that he needs to get his young, comatose son to the hospital. Ignoring his protests, the criminals force him to drive them out of the city to their hideout.
As they travel, Maria becomes increasingly anxious, causing frustration among Blade and Thirty-Two, who inappropriately harass her. Doc, trying to maintain control, instructs everyone to shut their windows. Yet, as the heat rises, he has them open the windows once again. When Maria asks for a stop to relieve herself, she seizes the chance to escape but is swiftly recaptured by Blade and Thirty-Two, who punish her by forcing her to urinate outside.
Later, the group makes a pit stop for food, with Riccardo buying sandwiches and drinks, while Thirty-Two opts for scotch. Tension breeds when a woman recognizes Riccardo; he quickly fabricates a story about a picnic with friends. Back on the expressway, Thirty-Two succumbs to intoxication and draws the attention of nearby motorists. Fearing the ramifications of his reckless behavior, Doc makes a heartbreaking decision and shoots him when he attempts to assault Maria. Although Thirty-Two survives, he is left incapacitated.
The group soon finds themselves in desperate need of petrol, leading them to a service station. When the attendant refuses to serve them immediately, Doc tries to intimidate him, only to be met with resistance as the attendant reveals he has a gun and recounts his own robbery history. To secure assistance, Blade forces Maria to plead with the attendant to fill up their vehicle for the sick child. A young woman appears, claiming her car has broken down and asking for help, as she pressures Doc for a ride. Unbeknownst to her, Thirty-Two's bloody hand is still in the vehicle. Although she fails to notice, the attendant does, making the situation increasingly precarious.
The hitchhiker, also named Maria, talks incessantly, unintentionally annoying everyone. When she inadvertently exposes Thirty-Two's injury, Blade, in a moment of panic, kills her. Doc then orders Riccardo to pull over so they can dispose of her body and, in a mercy killing, they also end Thirty-Two's suffering.
Finally arriving at their hideout—a crumbling villa where Doc has stowed a backup vehicle complete with papers to facilitate their escape—Riccardo and the remaining Maria are overjoyed. However, Doc coldly reveals his intention to eliminate them to ensure his own escape. Riccardo, desperately trying to save his unconscious son, begs for mercy. Unmoved, Doc commands him to remove the boy from the car. As Riccardo complies, he reveals a hidden weapon and shoots both Doc and Blade. Before succumbing to his injury, Blade retaliates, killing Maria.
In a shocking twist, we learn Riccardo harbors a sinister secret; he is a kidnapper. After securing the stolen money, he contacts the child's mother to demand a ransom of six million lire, promising to return with further instructions. With the child hidden in the trunk, Riccardo speeds away in his newly acquired vehicle, leaving chaos in his wake.
