During the
Ferragosto national holiday, Bruno, a thirty-six year old man, recklessly drives through the streets of
Rome in a flashy, expensive
Lancia Aurelia. Roberto, a timid and straitlaced law student, agrees to let Bruno use his phone, as Bruno is late for a meeting with friends; however, they have already left without him. Complaining that he was "only" an hour late, he insists on buying Roberto an apéritif to thank him. Tired of studying, Roberto accepts. They begin a road trip through
Lazio and
Tuscany along the
Via Aurelia. Roberto soon learns the essentials of Bruno's character: exuberant, coarse, charismatic, devil-may-care, impulsive, and immature. Bruno drives recklessly, constantly attempting "il sorpasso" — i.e., aggressively honking,
tailgating, and speeding to pass cars in front of him. Roberto has nothing in common with Bruno but is drawn to him. Bruno encourages Roberto to smoke, party, drink more, and ask out the woman he has a crush on. Roberto begins to doubt the tenets of his upbringing when he and Bruno stop to visit Roberto's relatives. Bruno points out to Roberto that his aunt has
cuckolded his uncle, and one of the relatives is openly nostalgic for fascism. At the same time, Roberto learns that Bruno is actually a failure in life and is running low on money. In the evening, Bruno impulsively visits his estranged wife Gianna and daughter Lilli. Over the course of a tense evening, Roberto learns that Bruno and Gianna impulsively got married in their early twenties; that Bruno is not involved in his daughter's life; that Bruno is withholding an
annulment from Gianna; and that Bruno stole 600,000 lire ($960, or about $10,000 in 2025) that Gianna had collected to bribe the
monsignor to approve the annulment. Gianna bitterly tells Roberto that one day is enough to understand Bruno, as he has no hidden depths. Bruno is shocked to learn that Lilli is about to marry Bibi, an older man who is more successful than him. He also hypocritically complains that Lilli has started smoking. He tries to seduce Gianna, but she angrily pushes him off the bed. With no place to stay, Bruno takes Roberto to sleep on the beach. The following day, Gianna, Lilli, and Bibi visit the beach for a cruise outing. Bruno hits on a young woman, who is actually Lilli in disguise. However, Lilli does not humiliate him, and Gianna invites Bruno and Roberto on the cruise, which Bruno takes as an invitation to reconnect with Lilli. He suggests that Lilli spend more time with him, but she avoids the question. Roberto hangs out with the women of the group, who compliment his personality, but due to his shyness, nothing comes of it. He attempts to call his crush as Bruno suggested, but chickens out. Although Roberto has wrestled with his admiration and dislike for Bruno throughout the trip, he finally resolves to be more like Bruno. Bibi explains to Bruno that he does not expect Lilli to love him, but will take good care of her anyway. In response, Bruno shocks Bibi by asking for a loan. Rebuffed, Bruno goads Bibi into betting 50,000 lire on a ping-pong match. He wins, but the gravely offended Bibi takes Gianna and Lilli on the boat and leaves without him. Bruno is briefly devastated, but quickly reasserts his carefree demeanor, revealing it to be a mask. On the drive back, Roberto adopts Bruno's mannerisms, shouting at other drivers and encouraging Bruno to drive more aggressively. Another driver gets
road rage and refuses to yield. Bruno recklessly pursues the car through
blind turns on a cliffside road. To avoid an oncoming truck, he swerves off the cliff, killing Roberto. When a police officer arrives and asks Bruno about the man who died, Bruno realizes that although Roberto told Gianna his last name, he has already forgotten it. ==Cast==