The Thea Sisters are headed to Venice, Italy. They'll be there for the Carnival, an annual festival that's famous for its elaborate masks. They mouse lets love exploring the city's bridges and canals and seeing the beautiful costumes mice wear to Carnival celebrations. But a mysterious thief strikes while they are there. Can they catch and unmask him before the festival ends?

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.