I died as a respected professor of anthropology—and woke up in the body of an unnamed youth in the middle of a tundra steppe, surrounded by cave hyenas. Around me is a harsh, primeval world from the last Ice Age. And in my head is the entire future history of mankind: its breakthroughs, its dead ends.
But no matter what knowledge I possess, here spear and instinct rule. And if I am to be heard, I must first earn my place by the fire. Only then will I be able to begin my real work: step by step, unnoticed by those around me, I will change the path of an entire species.