The actress embarks on the last leg of her epic river journey, flying to Juba in southern Sudan where the fragile peace process has enabled a re-emergence of the country's beauty pageants. She then heads to the Murchison Falls in Uganda and encounters some of Africa's wildlife - including hippos, rhinos and an unusual bird called a shoebill. Finally, Joanna meets explorer Cam McLeay who takes her to the source of the Nile, high up in the Rwandan mountains. Last in the series

The epic river journey brings the actress to Khartoum, where she watches whirling dervishes practising their devotional dancing and experiences a Sudanese beauty treatment that makes use of wood smoke. She then takes a short diversion into Ethiopia's Simien Mountains to meet an unusual group of Olympic hopefuls training in the thin air of the highlands

She begins her adventure on a fishing boat on Egypt's coast, where the Nile spills into the Mediterranean, before capturing the spirit of Agatha Christie in Cairo and enjoying a Nile cruise. She also travels along the river by train, road and felucca sailing boat, and ends the first part of her trip in Aswan, a town the Victorians described as being on the edge of civilisation.

The actress follows the river into the deserts of Northern Sudan, where she meets the survivor of a crocodile attack and goes in search of the creature. She is then introduced to the treasures of Nubia, an ancient kingdom of Africa ruled by the little-known Black Pharaohs, before visiting Sudan's capital city Khartoum, where she talks to nomads who live in the remote sub-Saharan desert.