The Doctor and Ace turn up at a World War II base by accident, just as vampiric monsters start to invade and an old evil known as Fenric is resurrected. Whilst the Doctor tries to take on Fenric, the soldiers descend into confusion and chaos, and Ace is confronted with her past. This episode was written during a period when the series was going for a darker, more mysterious, even untrustworthy Doctor - and this is reflected in the story's dark tones, and slightly more adult themes. The vampires are wonderfully realised creatures, either horrific bulbous grey monsters or long-nailed creepy girls. Whilst, perhaps the most frightening moment in the episode for the companion Ace, and the audience, is when the Doctor tells her, she is just a pawn in his plan.
