Geronimo Stilton, crusading news reporter and editor of The Rodent's Gazette, has been working too much and is in desperate need of a break. He is getting sleepy, very sleepy, but he can't actually fall asleep. Geronimo's cousin Trap tells him about a specialist, the Great Ratswami, who hypnotizes mice to help them relax. Shortly after Geronimo's meeting with the hypnotist, New Mouse City is plagued by a crime wave and Geronimo seems even more tired than ever! Something weird is going in New Mouse City, and the to-tally shocking answer will become front-page news!