In this fun spin-off to the bestselling middle grade adventure series, the prehistoric ancestor to Geronimo Stilton investigates a Stone Age mystery. Geronimo Stilton's ancient ancestor Geronimo Stiltonoot is back in another prehistoric adventure! A visiting rodent has arrived in Old Mouse City with astounding news. On his recent journey to a cold, distant land, he spotted a mountain . . . moving! Holey cheese! Geronimo Stiltonoot sets off on a trip to the ice and snow to find out what lies behind this mystery. It's a fur-raising expedition! Praise for the Geronimo Stilton's Cavemice series: "Fans of the other Geronimo Stilton books will definitely embrace the over-the-top silliness in this new spin-off." --Booklist Praise for Geronimo Stilton's books: "Lightning pace and full-color design will hook kids in a flash." --Publishers Weekly