Adventurer Simon Reeve travels from source to sea along the world's longest river, the Nile. His journey will take him from the holy source of the Blue Nile in the Ethiopian highlands, through the desert of Sudan and onwards through Egypt to the Mediterranean Sea. The life-giving river has forged some of our earliest civilisations and influenced some of our greatest religions. But with populations along its banks rising fast, Nile countries are demanding an ever-greater share of the sacred waters, threatening the stability of the entire region.

Simon Reeve follows the sacred waters of the Ganges from source to sea, exploring how India's economy has affected its religious culture. Along the way he meets westerners in Rishikesh seeking spiritual enlightenment, takes a holy dip in the fast-flowing waters at Haridwar and discovers how the river is being severely polluted in Kanpur. While there, Simon hears allegations that holy cows are secretly being slaughtered to fuel a booming leather trade. Finally, at Sagar Island in the Indian Ocean, Simon wonders how long India's age-old sacred river can survive its economic boom.

Simon travels along the Yangtze, discovering a revival of religious faith in China. Starting his journey at the first bend in the Yangtze, Simon follows the river to Dazu where he sees 50,000 ancient and exquisite rock carvings, some of the only religious artefacts not to have been destroyed under communist rule. Taking a river cruise, he arrives at the Three Gorges Dam, the biggest power station on the planet. Simon's journey ends in Shanghai, a shining symbol of China's new economic might but also a city where many are rediscovering religious faith.