After having their DNA tested, Ian Thorpe, Ernie Dingo, and Julia Zemiro set off on an epic journey of genetic time travel to find out where they, and the rest of humankind, come from. In this episode, they head towards the Serengeti plains in northern Tanzania, 20,000 years to the beginnings of humankind. They meet the Hadzabe people, one of the last remaining hunter-gatherer tribes on earth. Living off the land, they still use ancient methods to survive.

Julia and Ian journey to Israel and discover the percentage of Neanderthal DNA they each carry. Ernie's DNA reveals an ancient connection to the people of India. He makes his way south to the remote rural village of Isko, home to the Munda people, and discovers the deep and surprising links he has with this Indian tribe. Meanwhile in Australia, the unique genetic census of everyday Australians continues and DNA results reveal that identity really is more than skin deep.

In this final episode, Ian's in the grasslands of Kyrgyzstan in the former Soviet Union to discover how his ancestors' horse-taming skills and the invention of the wheel changed the course of human history. Julia Zemiro's father's ancestors were on the beautiful island of Sardinia, off the west coast of Italy. Ernie Dingo's genetic map leads him to Timor Leste, where he learns of humankinds' greatest ever achievements - the journey to arrive on the shores of Australia for the first time.