Geronimo Stilton's ancient ancestor Geronimo Stiltonoot is back in another prehistoric adventure! It's the season for the annual cavemouse sports competition! This year, Tiger Khan and his saber-toothed henchmen want to enter the games. They call a truce with the cavemice during the tournament . . . but when their flag goes missing, Tiger Khan is furious. Can Geronimo Stiltonoot track it down in time to keep his fur intact?