Warlock is an original novel written by Andrew Cartmel and based on the long-running British science fiction television series Doctor Who. It features the Seventh Doctor, Ace and Bernice. The book is the middle novel in the "War trilogy", following on from ' and concluding in Warchild. A prelude to the novel, also penned by Cartmel, appeared in Doctor Who Magazine #221.
A new drug called "Warlock" is tearing apart society. Benny is involved with a law enforcement effort to bring it down while Ace is in trouble in a horrific animal laboratory. Only the Doctor is left to discover the truth behind the new drug.