A coach is making its way along the icy road to Havre. Its passengers are silently eyeing one another, trying to reach the port in spite of the war-torn countryside and the advancing Prussian troops. Self-conscious of respectability, they are uncomfortable sharing a coach with “a member of the courtesan class,” who is nicknamed “Boule de Suif” (ball of fat) because she is so round. The journey is long and tedious, so that when Boule de Suif takes some food from her traveling basket and good-heartedly offers to share it among the others, the passengers—begrudgingly at first and then avidly—eat and drink their fill; even the two nuns indulge with comic delicacy. Before long, they are all talking amiably about patriotism and the evil Prussians.

That night, the coach stops at an inn behind the Prussian lines and the passengers are given separate rooms. During the night, officious Monsieur Loiseau keeps his eyes to the keyhole of his door, trying to observe “the mysteries of the corridor.” He sees the rogue Cornudet make advances to Boule de Suif, but she rebuffs him, insisting on maintaining her dignity in the midst of the enemy. A Prussian officer, the presiding “law” in that part of the country, has set up his headquarters in the inn and is staying in a room just down the hall. Under such circumstances, she tells Cornudet, one must keep one’s self-respect.

The next morning, the passengers find the coach unharnessed and themselves detained. They learn that the Prussian officer has forbidden them to leave until Boule de Suif gives herself to him. She is shocked and angry at the proposal, and, for a while, so are the other passengers. Days pass. The Prussian waits. Soon the passengers grow impatient, and the Prussian’s tactic of wearing down their shallow moral indignation begins to work. They begin to hatch their own strategy for getting Boule de Suif to capitulate. The wives talk to her of romantic self-sacrifice; the nuns, too, are enlisted, preaching to her of purity of motive. The men talk of war and glorious patriotism. Throughout lunch and dinner and into the evening hours the psychological assault on Boule de Suif continues. Ironically, only Cornudet, the old rogue, refuses to have anything to do with the scheme.

Finally, exhausted, confused, and burdened with guilt over being the cause of the group’s internment, Boule de Suif yields and gives herself to the Prussian. That night, the passengers celebrate victory. Loiseau “stands champagne all round.” Only Cornudet is sullen. “You have done an infamous thing,” he tells them.

Next morning, the passengers find the coach ready for their departure. Boule de Suif is the first to climb in, and at last they resume their journey. Now, however, the passengers snub Boule de Suif. They talk among themselves, showing her their disdain. Chatting amiably, they do not seem to care that in the dark corner of the coach Boule de Suif is silently weeping.