All the mammoths have fled Old Mouse City! It's a total cat-astrophe! Not only because mammoths are valuable allies of the cavemice, but also because without them, the cavemice can't make mammoth milkshakes, their delicious national drink. Geronimo Stiltonoot must embark on a daring journey to find the mammoths...and avoid going extinct before he gets back!

"Geronimo Stilton's ancient ancestor Geronimo Stiltonoot is back in another prehistoric adventure! It's 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?" --