Geronimo Stilton gets caught up in the World Karate Championships, thanks to the efforts of Bruce Hyena and Piccolo Tao, Bruce's super-sporty cousin. Geronimo only has a week to become real champion material! Will Geronimo manage to overcome his fears in order to win the competition?

When Geromino Stilton and his friends time travel to three different centuries seeking artifacts missing from the mouseum, they meet Alexander the Great, Queen Cleopatra, Francis Drake, and Mozart.

The enchanted Winged Ring which Queen Blossom gave to Geronimo is missing, apparently stolen by the dark fairy Wither and her dark crow allies, and whoever possesses it gains enormous power and can travel between the Kingdom of Fantasy and the real world--now nightmares are starting to affect Mouse Island, the entire Kingdom is furious with Geronimo, and it is up to one mouse to set things straight and recover the ring.