Nightshade is an original novel written by Mark Gatiss and based on the long-running British science fiction television series Doctor Who.

A prelude to the novel, also penned by Gatiss, appeared in Doctor Who Magazine #190.

The Doctor contemplates retiring and Ace falls in love with local boy Robin Yeadon.

In a nearby retirement home, Edmund Trevithick, who once played the fictional character known as Professor Nightshade in the BBC TV series of the same title, begins to see other fictional characters from the programme as if they were real.

The Doctor realizes that Crook Marsham has had many unexplained deaths throughout history.