When you're with Geronimo Stilton, it's always a fabumouse adventure! Geronimo is celebrating his birthday! He is out with his family when he realizes someone has replaced all of his money with counterfeit bills. Geronimo and Hercule set out to find the thieves!.

Geronimo Stilton is the pseudonym of the famous Italian writer Elisabetta Dami. She has written the famous series of books on Geronimo Stilton. She co-owns the Italian based publishing company called Edizioni Piemme. She likes to get all her ideas through her travels to places around the world.