Sylvain Pons earns a meager living conducting at the ballet and giving private music lessons. He is very fond of fine food and fine art. Over the years, he has satisfied the latter craving by slowly accumulating pieces that now clutter the small apartment he shares with his friend Schmucke. Sylvain doesn’t know it, but the collection is worth a surprising amount of money. He satisfies his taste for fine food by frequently going to dinner at his cousin Marville’s house.

Marville’s wife dislikes having Sylvain at her table, for he is rustic and abrupt. He is finally kicked out completely when he tries to find a suitor for the Marville’s daughter, Cecile, and bungles the job. Shortly afterwards, Sylvain falls ill. His portress, Cibot, enters the rooms to nurse him, recognizes the value of his art collection and schemes to get it. She gets Remonencq, who runs a nearby pawn shop, and Elie Magus, a Jew with an eye for art, to help her.

The attack begins when Cibot convinces Schmucke to sell some of Sylvain’s paintings in order to pay for the doctor bills. The plot thickens as Sylvain’s doctor and an attorney get involved. The attorney goes to Madame de Marville and convinces her to fleece Sylvain or risk a smaller inheritance from Sylvain. Her husband regretfully agrees also.

Meanwhile, Sylvain has become suspicious of Cibot. He struggles out of his sick bed to find Magus studying the collectibles in his bedroom. The other rooms are empty. Sylvain realizes his friend Schmucke has been duped, and he plans a counter-attack. He writes a false will, leaving all his money to Cibot for her service at his final illness. He leaves it where she will see it. He then writes a second, true will that leaves his money to the crown on the condition that they grant Schmucke a lifetime annuity.

Sylvain then dies. Schmucke becomes the new target of the others’ greed. They nearly convince him to sign a paper forfeiting most of his inheritance, but when he realizes that the Marvilles are accusing him of having duped their cousin he falls ill and dies. The money passes on to the Marvilles. The attorney gets an important new job; the doctor gets a sinecure, and Magus gets the pictures. Even Cibot is rewarded; she gets an annuity and marries Remonencq after he kills her husband.