On Michele’s freight barge, anchored in a corner of the Seine, the bargees are busy unloading. Giorgetta, Michele’s young wife, is vexed by her husband’s demonstrations of affection. During a break in their work she offers a drink to the bargees – Tinca, Talpa and the young Luigi. As a barrel-organ player goes past, she dances with Luigi, abandoning herself languidly in his arms. Work resumes when Michele arrives. He tells his wife that when the barge leaves the three men will be staying behind in Paris, which seems to annoy Giorgetta.

Frugola enters, looking for Talpa, her husband. Having finished his work, Luigi complains of the mediocre conditions of workers, and joins Giorgetta in her nostalgia for their common neighbourhood of origin in Paris. Left alone with the girl, Luigi muses on their last night of love and arranges their next nocturnal rendezvous with her. As soon as he sees the signal of a lighted match, he will come to her under cover of darkness.

Giorgetta retires to her cabin, waiting for her husband to fall asleep. But Michele stays on deck, wrapped in his cloak. He suspects that Giorgetta’s increasingly impatient attitude towards him is an indication of her unfaithfulness. He lights his pipe. Luigi, who has been waiting, takes this as the agreed signal and comes on board. Michele attacks him, forces him to confess his guilt, and then strangles him. He hides Luigi’s body under his cloak.

Giorgetta, who has heard the scuffle, joins her husband on deck and asks him to take her, as he used to do, into his arms. Michele opens his cloak, out of which rolls Luigi’s corpse. Giorgetta lets out a scream and Michele pushes his wife’s face close to that of her slain lover.