Thanks to The Book, Joe, Sam, and Fred are back in the Stone Age, where there aren't any math problems. But there's a tribe of hostile cavewomen, a hungry-looking saber-toothed tiger, a bone-rattling earthquake, and a woolly mammoth who wants to turn them into toe-jam. Worst of all, Joe, Sam, and Fred have discovered that writing hasn't been invented yet—so how can The Book get them back home?
Thanks to The Book, Joe, Sam, and Fred are back in the Stone Age, where there aren't any math problems. But there's a tribe of hostile cavewomen, a hungry-looking saber-toothed tiger, a bone-rattling earthquake, and a woolly mammoth who wants to turn them into toe-jam. Worst of all, Joe, Sam, and Fred have discovered that writing hasn't been invented yet—so how can The Book get them back home?
