Moose, Goose, and Mouse all live in a house, but the house is old, wet, and cold. So, they decide to take the train to look for a new house. Mouse wants a house that's sunny, Moose wants a house that's funny, and Goose wants a house with a bunny. On the way, the caboose breaks free from the train and goes careening down the tracks. It comes to a stop upside down by a tree near the sea. To their delight, they realize that they have a sunny, funny, loose caboose for a house with a bunny.