Michel is a young petty criminal who models himself after film icon Humphrey Bogart. After stealing a car in Marseille, Michel shoots a police officer who was following him on a country road. Penniless and on the run, he turns to his American girlfriend Patricia, a student and journalist who sells the New York Herald Tribune on the streets of Paris.

Unaware that he is being pursued by the police, Patricia unknowingly hides him in her apartment. Meanwhile, Michel tries to seduce her and convince her to flee with him to Italy using her money. At one point, Patricia tells him she is pregnant with his child, but soon after, during police questioning, she learns that Michel is a fugitive.

In the end, she betrays him, but confesses what she did just before the police arrive. Michel, initially resigned to going to prison, suddenly changes his mind and tries to flee. The police shoot him in the street; he manages to run a short distance before collapsing and dying.

Michel’s death scene in Breathless (À bout de souffle) is one of the most legendary in cinema history, though the final lines of dialogue have caused some confusion for English-speaking audiences. In some translations, it's unclear whether Michel is condemning Patricia specifically, or making a broader statement about the world.

The film is subtitled in English.