Necessity is the mother of invention and this is exactly what the Five Nice Mice learn in their new adventure. They search for a new place to live because the cats in their neighborhood make life too dangerous. What they find is a mountain of things that have been discarded. The city dump becomes a mountain of treasure and they find everything they need to build their dream house. But their dream almost comes to an end when a cat comes to their new neighborhood. The little mice are able solve this problem too, with a bit of understanding and a lot of heart.