. "Conundrum"@en . "ISBN 0-426-20408-5" . . . . . . . . "Conundrum is an original novel written by Steve Lyons and based on the long-running British science fiction television series Doctor Who. It features the Seventh Doctor, Ace and Bernice. A prelude to the novel, also penned by Lyons, appeared in Doctor Who Magazine #208. This novel is the fourth book in the \"Alternate Universe cycle\" which continues until No Future."@en . .