Classic Doctor Who: Battlefield

The TARDIS materialises in the English countryside near the village of Carbury, where a nuclear missile convoy under the command of UNIT's Brigadier Winifred Bambera has run into difficulties. Lying on the bed of the nearby Lake Vortigern is a spaceship from another dimension which contains a very special passenger.

The Brigadier falls victim to Morgaine's powers as he approaches the town in a helicopter. The Doctor and Ace discover a tunnel that leads under the lake, where the Doctor comes to a surprising realisation about his future.

The battle rages between Mordred's troops and the UNIT forces, but the Doctor and the Brigadier try to intervene as there is a nuclear missile on the battlefield. Meanwhile, Morgaine has a different plan to help her seize Excalibur for herself.

Morgaine has gained possession of Excalibur so the Doctor and the Brigadier set off after her through the vortex tunnel. When Morgaine unleashes the Destroyer demon, the Doctor decides to awaken King Arthur to let him finish the fight.