In the not-too-distant past, humans shared this planet with other species of hominid. This series tells how, against all the odds, Homo sapiens survived. This episode is set 75,000 years ago in India, following a catastrophic super-volcanic eruption which forced a showdown between our ancestors and a completely different species of human, Homo erectus, who up until that point had reigned supreme.

This episode is set 35,000 years ago and depicts Homo sapiens's encounter with Homo neanderthalensis. As the ice caps retreated, the Neanderthal stronghold in Europe weakened, providing a window of opportunity to which modern humans owe their existence.