Pierre, Manuel Blanc, an idealistic twenty-year-old, leaves his home in a remote district of the Pyrenees to travel to Paris, hoping to break away from his restrictive provincial life. Arriving in the French capital, he turns to Evelyne, Hélène Vincent, a middle-aged nurse he had briefly met when working as a stretcher-bearer at Lourdes. She is vague and distracted, being preoccupied by the paralyzed mother with whom she lives. Nevertheless, she manages to get Pierre a job in the kitchen of a hospital. He finds somewhere to stay and, in order to fulfill his childhood dream, buys a book on how to become an actor.
A colleague at work, Roschdy Zem who plays Said, takes him to dinner with two middle-aged men: Ivan Desny as Dimitri, the cellist who is Said's lover, and the intellectual television personality, Philippe Noiret as Romain, who is fascinated by Pierre but insists his interest is platonic. Pierre is disgusted by the evening and when Romain gives him a ride home and stops in a park that is a pick-up point for hustlers, he walks off in a huff, refusing to get back into Romain's car. Evelyne takes Pierre to an expensive restaurant to make up for her earlier indifference. They return to her house and spend the night together. She offers him free accommodation; he moves in and they start an affair.
Pierre begins to attend acting classes but shows little talent. When he has to prepare for "Hamlet", he recites the role with no feelings and even forgets his lines. Humiliated, he flees in abandonment from his tentative ambition to become an actor.
His relationship with Evelyne also comes to an abrupt end. She feels that he does not really love her and breaks away from him. When she leaves him some money, Pierre feels insulted, returns the money, and leaves the place she had offered him. He goes absent from work pleading illness and eventually loses his job. Homeless and forced to sleep on the streets, he falls victim to thieves who steal all his belongings. Now broke and homeless, Pierre returns to the park where Romain took him in, and sees him again. Pierre's offer of sexual favors is refused, but Romain takes him on a trip to Spain. In Seville, the older man takes someone else as a lover and Pierre returns to Paris.
With no job or home, Pierre has to adopt prostitution as his only way to make money. He makes his rules very clear to prospective male clients:
> I don't kiss, I don't suck, I don't get fucked
Despite his initial aversion to sex with men, Pierre manages to make a success of his new career. During a police crackdown on streetwalkers, he meets Ingrid, Emmanuelle Béart, another prostitute. He becomes infatuated with Ingrid, whose dream had been to become a singer. Both are arrested and after a night in jail, they spend an idyllic day together. They make love, but their liaison is discovered by her pimp, who with his gang beats up and rapes Pierre, forcing Ingrid to watch.
Pierre leaves Paris and joins the paratroops; he voices to an interviewing officer a desire for revenge, and also for the "leap into the void" involved in parachuting at night. On a visit home, he tells his brother that he did not hate the city, he just was not ready for it. On release from his service, and about to leave once again for Paris and an open future, Pierre stops off at the beach, takes his clothes off and wanders into the sea.
