Rent Doctor Who: The Androids of Tara (1978)

It seems that the search for the fourth segment of the Key to Time will prove simple when Romana locates it on the planet Tara. But in a land where nothing is as it first appears, the Doctor and his companion quickly find themselves embroiled in a deadly game of kidnap, deceit and counterplot. It is not long before the Doctor himself is locking swords with the dastardly Count Grendel of Gracht, the finest bladesman in the kingdom, who has sinster plans for Romana...