Geronimo Stilton's ancient ancestor Geronimo Stiltonoot is back in another prehistoric adventure. Geronimo Stiltonoot and his family are off to find a cure for Grandma Ratrock's aches and pains. She's heard that a remedy hides in a legendary valley, and Geronimo isn't even sure it exists. Little does he know that getting there will be an adventure among geysers, volcanoes, and rivers of molten lava.

"Geronimo Stilton's ancient ancestor Geronimo Stiltonoot is back in another prehistoric adventure! It's the night of the big Cavemouse Idol competition, but Geronimo Stiltonoot isn't there. He has a cold, and goes to bed early. So when it's discovered that the contest's valuable grand prize has been stolen, Geronimo is the main suspect! He must prove his innocence . . . or he'll end up in enormouse trouble!" --

"Geronimo Stiltonoot and The Stone Gazette are in the running for the Stone Age Ratitzer: the award for the best prehistoric journalism! But their main competition is Sally Rockmousen, the ruthless host of Gossip Radio--and she'll stop at nothing to win. Can Geronimo sniff out a scoop in time to defeat her?" -- Page [4] cover.

Geronimo Stiltonoot and his family save a young dinosaur from the river. The dinosaur and Benjamin quickly become good friends, but the dino turns out to have a tremendous talent for mischief. Can Geronimo get him back to his herd before he causes a megalithic disaster?

When the Cavemice discover a giant oyster in the lagoon near Old Mouse City, they call on Geronimo Stiltonoot to help them fish it out of the water before the saber-toothed tigers find the pearl.

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 and his friends participate in a treasure hunt set up by his rival and are determined to overcome all of its challenging obstacles, including tricky riddles and smelly dinosaurs.