The best stories should never be unwritten... When a strange signal echoes through time to the heart of the TARDIS, the Doctor follows it to the home of Shirley Jackson. But the strangeness deepens when they find a sinister figure sowing chaos and discord with the use of a glowing box - encouraging a crowd to murderous deeds. Catapulted back to Shirley Jackson's own era by the TARDIS, the Doctor (with the help of the time-struck author) must discover the origins of the box, and the terrible power that it wields...