From his back garden Robert Twigger can see kingfishers swooping and crocodiles emerging from the grey-green expanse of the Nile. Never ending, as wide as a lake in places, the Nile continually snakes its way north to the sea. It's a river steeped in history, and as Twigger searches for its source and probes its ancient, biblical and more contemporary existence, he uncovers the Nile's bloody, murderous past.