Prehistory is all around us. We just need to know where to look. Juan José Millás has always felt like he doesn't quite fit into human society. Sometimes he wonders if he is even a Homo sapiens at all, or something simpler. Perhaps he is a Neanderthal who somehow survived? So he turns to Juan Luis Arsuaga, one of the world's leading palaeontologists and a super-smart sapiens, to explain why we are the way we are and where we come from. Over the course of many months, the two visit different places, many of them common scenes of our daily lives, and others unique archaeological sites. Arsuaga tries to teach the Neanderthal how to think like a sapiens and, above all, that prehistory is not a thing of the past: that traces of humanity through the millennia can be found anywhere, from a cave or a landscape to a children's playground or a toy shop.