Air: Feb. 22 1964. 7 eps., all lost
The Tardis lands in the Himalayas where they meet a traveling band of Mongols led by Marco Polo. He decides to give to Kublai Khan the Tardis as a gift. Can The Doctor and his crew convince him to change his mind? Meanwhile, there is a sinister spy within planning to bring about the fall of the Khan.
This serial is the first of a line of lost Doctor Who episodes. In England, they wiped their own TV shows. However, the audio survived and is available through audio CDs. Or you can watch reconstructions of them made with the audio and photos and surviving footage made by fans online.