Ofelia and Philémon are on their way home to Sweden to celebrate Christmas with their grandmother. Their father mostly plays cards in the parlor so they have to take care of themselves. When the father discovers that some rats have eaten the money that was in a chest in their cabin, the children are promised a penny for every rat's tail they can get. But the rats Lucky Closette and Don Calzone hear this and Lucky, being a mischievous sewer rat, has a plan to stop them.
