Neanderthals were stronger, better adapted to cold, and armed with weapons capable of killing prey up close, yet they vanished while a physically weaker species survived. This film asks why, using new fossil analysis, DNA evidence, and interviews with researchers who study the overlap between Neanderthal and early modern human populations in Europe. It covers the physical evidence for interbreeding, the genetic traces of Neanderthal DNA still present in living humans today, and grislier finds including butchered bones that point to cannibalism among Neanderthal groups. Researchers walk through excavation sites and labs, explaining how tools, diet, and skeletal remains are reread with modern techniques to challenge the old image of a slow, doomed brute. The film weighs competing explanations for extinction, from climate shifts to competition for resources to violent conflict with incoming Homo sapiens, without settling on a single verdict. It treats the Neanderthal story less as a closed case than as a relative whose fate, and whose genes, still shape the species that replaced them.