Episode 2 ‘Lost Worlds’ picks up the journey at the Pamir Mountains on the edge of China, from where Marco Polo follows the Silk Road, down to the forbidding Taklamakan Desert and onto the Mongolian steppe. He makes his way to Xanadu, the heart of Kublai Khan’s power base. Along the way we meet the modern guides on the ancient horse-drawn postal routes and discover the City of Women in modern day Tibet.