“Battlefield” is the first adventure of the twentysixth season of “Doctor Who” classic series which aired in 1989 featuring the Seventh Doctor and Ace. It follows “The Greatest Show in the Galaxy” and it’s a four parts adventure written by Ben Aaronovitch and directed by Michael Kerrigan.

Responding to a distress signal, the Seventh Doctor (Sylvester McCoy) and Ace (Sophie Aldred) arrive near Lake Vortigern in England. There, UNIT is having some problems with some nuclear missiles and things get worse with the arrival of some knights in medieval armors who also use energy weapons.

The situation and the presence of the Doctor lead to recalling Brigadier Lethbridge-Stewart (Nicholas Courtney) from his retirement. Together with Ancelyn, a knight of King Arthur, they’ll face the witch Morgaine and her warriors, arrived from a parallel universe, who think that the Doctor is Merlin.