S1, E2: Around 70,000 years ago, Ian, Ernie and Julia's ancestors lived in what we now know as the Arabian Desert. But much has changed through the course of human history. This arid, unforgiving desert was once a very different place. Archaeologist Jeff Rose has been studying the region for the past decade, and reveals to the three travellers that this was once a lush green expanse. To unearth more secrets of the past, the three go deep into the desert in search of the stone tools their ancestors used for everything from hunting to cutting. Hoping to channel the skills of his ancestors, former Olympic champion Ian attempts to make his own stone tool, but soon discovers it's not quite as easy as it looks.