Even though Geronimo Stilton isn't exactly known for taking risks, he can't always say no to adventure -- especially when he's invited to be the first time-traveling mouse! But Geronimo's invitation does come with a catch. Professor Paws von Volt doesn't just want him to observe the past; Geronimo must investigate what caused the dinosaur extinction. Will Geronimo solve one of history's greatest mysteries, or will this time-traveling mouse end up...

On a school field trip to the famous Lascaux Cave in southern France, a young girl encounters a primitive man who had created the remarkable paintings on the cave's walls. Includes a section with information on early homo sapiens.