Lottie La Belle loves her dog Patrick very much. Patrick won't eat vegetables, so why should she? Lottie turns to eating bread and cheese morning, noon and night. Her piano teacher is the first to notice a change. Eeek! What's that mouse tail doing dangling from under Lottie's skirt? Soon Lottie is a fully-fledged mouse, but when the neighbourhood cats plot against Lottie, something extraordinary happens…