For cavemouse Geronimo Stiltonoot, life is one prehistoric problem after another! In the lagoon near Old Mouse City, cavemice have discovered a giant oyster. It holds a pearl of megalithic proportions! Since the mice of the lagoon don't have the tools to fish the oyster out of the water, they call on Geronimo Stiltonoot to help. Can figure out how to get the pearl before the saber-toothed tigers catch wind of it?

For cavemouse Geronimo Stiltonoot, life is one prehistoric problem after another! Geronimo Stiltonoot is competing in a race to Boulder Bay and back! It's dangerous, but it will supply the village cheese maker with rare hot lava peppers, and there's a big prize for the winner. Unfortunately, Geronimo has a lazy, slow, city autosaurus (the cavemice mode of transportation). Can he reach the finish line without going extinct on the way?

Geronimo Stilton's ancestor, Geronimo Stiltonoot, searches for Tiger Khan's missing flag to prevent chaos during the annual cavemouse sports competition.

Spacemouse Geronimo Stiltonix's adventures are out of this world! The on board computer on spaceship MouseStar 1, Hologramix, is out of order! To fix it, Geronimo Stiltonix must take it to a brilliant inventor who lives on a distant planet. But while Hologramix is being repaired, pirate spacecats attack, and steal it! Can the spacemice get Hologramix back before the spacecats turn it evil and set it against them?

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!

Oh, no! One of the special miceking helmets in miceking leader Sven the Shouter's private collection has been stolen! Could it have been taken by the vilekings-the rival mouse clan? The micekings journey to the vilekings' village to find out... and while they're there, the dragons attack! Can all the mice work together to save their fur?

Geronimo unlocks the mystery in this fabumouse adventure -- which includes a bonus story! My sister, Thea, had discovered an enormouse old castle built by the founder of New Mouse City! She and Trap dragged me along with them to explore it. Inside, we found one hundred keys... but only ninety-nine doors to unlock. What mysterious room did the hundredth key open? It was up to us to find it and reveal its secrets! BONUS! After the story, read an extra Mini Mystery adventure and jokes galore!