For cavemouse Geronimo Stiltonoot, life is one prehistoric problem after another!

This time, Geronimo is competing in a daring race to Boulder Bay and back. The journey is dangerous, but the prize is worth it — not only will the winner bring home rare hot lava peppers for the village cheesemaker, there’s also a big reward waiting at the finish line!

But there’s one small problem… Geronimo is stuck with a lazy, slow city autosaurus, the worst racing partner imaginable. Can he cross the finish line — or will he go extinct on the way?