The village of Carbury, England, in the late 1990s, where a nuclear missile convoy overseen by UNIT has run into difficulties. Lying on the bed of the nearby Lake Vortigern is a spaceship from another dimension containing the body of King Arthur and ... (more)his sword Excalibur.

Angela Bruce, Angela Douglas, Christopher Bowen, James Ellis, Ling Tai, Marcus Gilbert, Noel Collins, Robert Jezek