A story of courage and adventure, set against the backdrop of the race to exploit Africa by the colonial powers. For millennia the location of the Nile River's headwaters was shrouded in mystery. In the mid-19th century, Richard Burton and John Hanning Speke were sent by the Royal Geographical Society to claim the prize for Britain.

Burton spoke twenty-nine languages, and was a decorated soldier. He was also mercurial, subtle, and an iconoclastic atheist. Speke was a young aristocrat and Army officer determined to make his mark, Burton's opposite in temperament and beliefs.

From the start the two men clashed. They would endure tremendous hardship, illness, and constant setbacks. Two years in, deep in the African interior, Burton became too sick to press on, but Speke did, and claimed he found the source in a great lake that he christened Lake Victoria.

When they returned to England, the two became sworn enemies. Yet there was a third man on both expeditions, his name obscured by imperial annals, whose exploits were even more extraordinary. This was Sidi Mubarak Bombay, who was enslaved and shipped from his home village in East Africa to India.

When the man who purchased him died, he made his way into the local Sultan's army, and eventually travelled back to Africa, where he used his resourcefulness, linguistic prowess and raw courage to forge a living as a guide. Without Bombay and men like him, who led, carried, and protected the expedition, neither Englishman would have come close to the headwaters of the Nile, or perhaps even survived.