In the continuing adventures of Neanderthal siblings Lucy and Andy, their family is joined by a group of early humans, and as the cold weather sets in, the two groups struggle to comfortably live together in a too-small cave. While Lucy easily makes friends with the new kids, Andy's feeling chaffed by the close quarters, and he's eager to help the humans find a new cave to live in, though his reasons are far from altruistic. In between Brown's spot-on depiction of kid jealousies, braggadocio, and bravery among the kids from both groups, a pair of paleontologists appears to offer scientific background on what life might have been like 40,000 years ago and how scientists have made those discoveries. The fictional narrative provides a nice framework for the background context, and the tone of the paleontologists' lesson is lighthearted and sometimes silly. Brown's cartoonish figures, rendered in pleasantly jittery lines, are full of character, and his comedic timing shines in his panel layouts. For fans of the series opener or kids who like learning about prehistoric eras.

Neanderthal siblings return for a blustery infoventure in the Ice Age.Lucy and Andy meet and welcome into their cave an extended, racially diverse family of humans. Andy is less than enthusiastic about the arrangement, but Lucy is glad to have Sasha, a little black girl, and the others to pal around with. Between hunts for food, the adults search for a nearby cave for the humans to move into. The kids play in the snow, do chores, visit a glacier, and visit the Neanderthal family's summer cave at the beach. Can the families outsmart cave bear Big Bob and appropriate his cave for the humans, or will they live together forever? Modern-day fictional commentators Pam (a white woman) and Eric (a black man) return as well to explain (usually with jokes) and expand on the actual science and discoveries behind the events in Lucy and Andy's comic-strip adventures. Science-y tidbits dot the narrative panels (usually followed by sarcastic one-liners), and the whole is followed by a museum list, a Q-and-A, and myth-busters about cavemen, all conveyed in a light tone. No further reading or works cited make this problematic as an informational source, but for the paleontologically inclined, it's a fast, funny read with likable kid characters. Captivated kids will be happy to see that Book 3 is on its way. (Graphic historical fiction. 9-12)