Frankincense once sold for more than its weight in gold, and the trade route that carried it out of southern Arabia ran roughly 2,000 miles north into the Holy Lands, crossing what are now Oman, Yemen, Saudi Arabia, Jordan, Egypt, Israel and Palestine. Presenter Kate Humble follows that route on the ground, riding with camel caravans' modern descendants and meeting the traders and growers who still tap the resin from Boswellia trees. She talks with Bedouin nomads in the desert and with city dwellers in ports the trade built, tracing how a single aromatic commodity, burned by Pharaohs and Caesars alike, connected economies and cultures across the ancient world for three thousand years. The film moves through blistering heat and shifting political terrain as Humble asks what the frankincense trade actually required of the people who ran it, and what is left of that world now that the resin's value has faded. History and present-day life sit side by side throughout, one explaining the other.