On the eve of May Day, dark elemental forces begin to disturb the village of Devil's End as the Master summons the demon Azal: unexplained murders, a stone gargoyle come to life, and a nigh-impenetrable infernal energy dome. With the Master fully prepared to destroy the Earth, the Doctor and UNIT - aided by a benevolent practitioner of witchcraft - battle the wicked rites of a secret science wielded by an alien from another world.
Jon Pertwee
The Doctor
Katy Manning
Jo Grant
Nicholas Courtney
Brigadier Lethbridge-Stewart
Richard Franklin
Captain Mike Yates
John Levene
Sergeant Benton
Roger Delgado
The Master
Stephen Thorne
Azal
Stanley Mason
Bok
