Cut off from the TARDIS, the Doctor and Leela find themselves stranded on a small island.  But they are not alone.  It is 1907, and members of the Caversham Society have gathered on the hundredth anniversary of the death of Mannering Caversham, the greatest Magic Lanternist who ever lived.

But Caversham was also a supernaturalist who claimed to have conjured up a demon from the depths of hell. As people start to die, the Doctor begins to wonder if Caversham’s story might have more than a grain of truth in it. Can the Doctor and Leela discover what really happened to Caversham a century ago?  And if they do, will they live to tell the tale..?