The Doctor is chosen for a quest by The White Guardian to go in search for the six segments to the Key to Time, that have been scattered and sent throughout the time/space continuum. With the Key to Time, The White Guardian will restore balance to the universe. Joined by a young time lady named Romana, The Doctor, Romana and K-9 Mark 2 begin their quest and arrive at their first destination, The medieval Russian like world Ribos, where a conman named Garron bids to sell Ribos to a exiled tyrant known as Graff Vynda K, where Unstoffe, Garron's assistant uncovers Garron's scheme and is unaware he is in possession of the first segment of the Key to Time. Written by
Did You Know?
In this serial (and much of the following one), Tom Baker
has a clear disfigurement of his upper lip. A few days before production began, Baker was bitten by a Jack Russell terrier belonging to Paul Seed
(Graff Vynda-K). The makeup team did what they could to cover up the injury with a bit of plaster, but it was still plainly obvious. The problem was explained in-story when the TARDIS lurches, and the Doctor's face bangs into the console. See more
You want me to volunteer, is that it? And if I don't?
You mean nothing'll happen to me?