An exciting journey back in time to the world of our ancestors! Thirteen-year-old Isabelle is spending her vacation with relatives in southern France. During an outing, she and her cousins discover the entrance to an Ice Age cave. Inside, the teenagers find 20,000-year-old evidence of Cro-Magnon people: skeletons, tools, and beautiful cave paintings. But then something terrible happens! A landslide cuts Isabelle off from the others.