Geronimo has always been a 'fraidy mouse, and his super-sporty friend Bruce Hyena decides that he needs to help Geronimo learn to keep calm in extreme situations. Bruce puts Geronimo to the test through encounters with scary animals and weather in conditions ranging from the desert to the North Pole. After Bruce's crazy training, a natural weather disaster occurs on Mouse Island. Will Geronimo prove that he truly is a super mouse?