When their cave becomes overcrowded with humans, Neanderthal siblings Lucy and Andy start pulling pranks to make some room.

Lucy and her goofball brother Andy, two Neanderthal siblings living 40,000 years ago, take on a wandering baby sibling, bossy teens, cave paintings, and a mammoth hunt. But what will happen when they encounter a group of humans? Includes a special paleontologist section that helps to dispel common Neanderthal myths.