The TARDIS arrives on present day Earth where the Doctor and Ace investigate a distress signal, only to discover knights from another dimension led by the evil sorceress Morgaine and her son Mordred have arrived in our dimension to seek out Excalibur, the mythical sword of power of the legendary King Arthur. The Doctor is mistaken for Merlin, and the Doctor believes Merlin may be his future incarnation. Reuniting with Brigadier Lethbridge Stewart, The Doctor, Ace, a young Chinese woman named Shou Yuing, U.N.I.T officer Brigadier Winifred Bambara and a knight named Ancelyn set out to stop Morgaine and her knights unleashing the demonic Destroyer of the Worlds and prevent Morgaine and Mordred from destroying the planet with a nuclear warhead that U.N.I.T is transporting across the countryside. Written by
Did You Know?
The last appearance of Alastair Lethbridge-Stewart on _''Doctor Who'' (1963)_, save for an appearance in the one-off charity episode _"Doctor Who" The Dimensions of Time (1965)_ (though the canon status of that special is in doubt). Although the character has been mentioned in episodes of Doctor Who, he has yet to appear in the revived series. Nicholas Courtney
would reprise the role in 2008, however, as a guest star in a two-part episode of _''The Sarah Jane Adventures'' (2007)_. See more
Flight Lieutenant Lavel
[the Brigadier and Lavel have just escaped from a helicopter crash
Sir, we don't know what the situation is here!
The situation, Lavel, is normal, and it doesn't get much worse than that. You know, I'm rather enjoying this.