Professor Nightshade - tea time terror for all the family, and the most loved show in Britain. But Professor Nightshade's days are long over, and Edmund Trevithick is now just an unemployed actor in a retirement home, fondly remembering his past.
It's the same through the entire village of Crook Marsham - people are falling prey to their memories. At first harmlessly, and then, the bodies begin to turn up.
The Doctor and Ace arrive on the scene - but, with the Doctor planning his retirement, it may be time for Professor Nightshade to solve one last case.
Nightshade is based on the novel by Mark Gatiss from the Virgin New Adventures series of Doctor Who books.