Geronimo Stilton meets the Stone Age in this new spin-off series! Who is Geronimo Stiltonoot? He is a cavemouse — Geronimo Stilton's ancient ancestor. He runs the stone newspaper in the prehistoric village of Old Mouse City. From dealing with dinosaurs to dodging meteorites, his life in the Stone Age is full of adventure! In Watch your tail!, Geronimo Stiltonoot wakes up to a terrible morning. Meteors are falling from the sky, and it seems like everyone in Old Mouse City has an awful stomachache! Geronimo must travel to the Cave of Memories to find the ancient shaman cure for his fellow cavemice. But dangers lurk on his journey; can he make it back home safely?