A psychological novel narrated in second person and set on an overnight train to Rome. The center of the narration, a Parisian, is en-route to his affair partner to assure her he will leave his wife and that they can finally start a life together back in Paris. Along the trip he stares out at the landscape and watches his fellow passengers, visages that cause him to reminisce on his wife and mistress and daydream about their reactions to the news he intends to bring them both.

Ultimately, through these ruminations he realizes he doesn't really love his affair partner, she only serves as a stand in for his affection of Rome, and that bringing her to Paris will improve nothing and he'll still be miserable. It's not clear at the end of the novel what his course of action will be. Will this realization cause him to return to Paris to his family? Or will he stay in Rome, if not for his affair partner, then for the city itself?