Once a modest farmer, the patriarch of the Delorme family has made a killing when he sold his land to a railway company. Following in his footsteps, his son Louis-Dollard has built a luxurious apartment building in the center of town and is now a wealthy landlord. At his father's death, he robs his brother of his inheritance in order to build a house designed like a bank, with brass-grilled counters and an underground vault hidden behind the furnace. The vault's ceiling is covered with a mosaic of verdigris pennies, and its walls are painted with the same green ink as dollar bills. Louis-Dollard, his miserly wife Estelle and his three spinster sisters love money so much that they literally revere it, with the Green Chamber serving as their place of worship. They have elevated domestic penny-pinching to an art form. And they intend for their heir, Vincent, to make a highly profitable marriage. The arrival, in the neighborhood, of a rich young woman, Penny Sterling, makes them even greedier. They pull all stops to seduce her into joining the family. But Vincent will have none of it, nor will Penny. Together, they conspire to set fire to the Green Chamber - and bring the family down.