In the fourth episode, Roberts discusses the surprising evidence of the Mungo Lake remains, which suggest, surprisingly, that humans reached Australia long before they reached Europe, even though Australia is further away from Africa. Roberts attempts to trace the journey. She visits a site in India that appears to indicate that humans were present there 70,000 years ago, before the Toba supervolcano deposited ash on the site. She then points to the Negrito people of Southeast Asia, who look different from other Asian peoples, and who may be descendants of the peoples who first left Africa. She describes the discovery of the tiny homo floresiensis on Flores and suggests that they may have been exterminated by modern humans. She describes the crossing of the Torres Strait by experimenting with a bamboo raft. She concludes by visiting a tribe in Northern Australia whose mythology describes their mother goddess arriving from across the sea.