What are you afraid of? The Doctor, Harry and Sarah Jane Smith arrive at a remote Scottish island, when their holiday is cut short by the appearance of strange creatures -- hideous scarecrows who are preying on the local population. The islanders are living in fear, and the Doctor vows to save them all. But it doesn't go to plan -- the time travellers have fallen into a trap, and Scratchman is coming for them. With the fate of the universe hanging in the balance, the Doctor must battle an ancient force from another dimension, one who claims to be the Devil. Scratchman wants to know what the Doctor is most afraid of. And the Doctor's worst nightmares are coming out to play...