The tenth title in this gripping, dramatic and completely engrossing series - designed to engage reluctant readers (high interest, low-level reading), and anyone interested in battles, history, time travel, adventure, great stories, gadgets galore ...Mission 10: Caveman Bash - book no.91: the Stone Age - 30,000 BC, Ebro River, Northern Spain. Mission objective: To find out what happened to the Neanderthals. But Battle Boy's mission doesn't begin well. His brother Monty has followed him into the Battle Book. And then they meet the fierce Cro Magnons.