This was the first book and it was really light-hearted and cute! I love how we got introduced to scary, fraidy-mouse name Geronimo Stilton, who writes for the newspaper on mouse island. His sister brings him a map for a mysterious treasure and they go on an adventure.I received this book for review through NetGalley. This is the first title in the Geronimo Stilton series featuring the eponymous mouse (I could hardly call him a “hero”, but he is one of sorts) and characters now familiar from the book I read earlier, Geronimo’s sister Thea, their slightly annoying cousin Trap, and nephew Benjamin. In this one, the somewhat cowardly Geronimo is taken out to lunch by his sister Thea who informs him that she has found a map to a treasure island and intends to go find it, and expects that he Geronimo will accompany her. She also decides that cousin Trap will join them since he knows all about sailing. So off they go on a rather long sea voyage to the island where the treasure lies. But the journey isn’t the only adventure, once there, they must interpret the map and find the treasure. Geronimo isn’t the most adventurous of mice but in this one, he did quite well, once he got there.