Three convicts - Joseph, Albert and Jules - escape from prison on Devil's Island just before Christmas and arrive at a nearby French colonial town. They go to the store of the Ducotels - Felix and Amelie, and their daughter Isabelle - the only store that gives supplies on credit. Whilst there, they notice that his roof is leaking, and offer to fix it. They do not actually intend to fix it, but decide to remain there, until nightfall, when they will steal clothes and supplies, and escape on the ship waiting in the harbour. As they stay in the store, they find that the family is currently in financial distress and offer their services to hide their all-too-sinister ruse. Joseph even gets to work conning people and falsifying records to make the store prosperous. However, the three felons begin to have a change of heart after they fix a delicious Christmas dinner for the family: mostly made of stolen items.
Andre Touchard, who owns the store but lives in Paris, arrives on the island with his nephew Paul, with whom Isabelle is infatuated. The two plan on taking control of the store due to a lack of profit from the use of credit. Also, Paul is betrothed to another woman, which dismays Isabelle. Before any action against the Ducotels is taken, both of the men are bitten by Albert's pet viper, Adolfe, and they die nearly instantly. Isabelle finds another love, and the family is happy as the convicts successfully make their final escape. While waiting on the docks for their boat to arrive, the three escaped men finally decide to turn themselves back in at the prison, judging that the outside world was likely to be worse than that of the prison. As they walk away in the final shot, angelic halos appear over each of their heads...and finally another pops up over the cage of Adolf.