The Doctor and Ace receive a mysterious distress signal and land in the Earth village of Carbury, where a nuclear convoy has halted. The Doctor's concern is heightened when knights from another dimension begin to land in the area. Nearby is Lake Voortigen, the mythical resting-place of Excalibur, King Arthur's mystical sword...

But the lake holds a more sinister secret. A spaceship from the same alien dimension lurks under the lake - but does it really contain Arthur's corpse? And what is it that the Witch Queen, Morgaine, is really after?

The Doctor and Ace receive a mysterious distress signal and land in the Earth village of Carbury, where a nuclear convoy has halted

doctor who, battlefields, king arthur, action