Wolfsbane is a BBC Books original novel written by Jacqueline Rayner and based on the long-running British science fiction television series Doctor Who. It features both the Fourth and Eighth Doctors, Sarah Jane, and Harry, although the two Doctors never meet- their sequences taking place a month apart as the Eighth tackles the main crisis with Harry while the Fourth and Sarah tie up the loose ends a month later when they attempt to return to pick Harry up- and with nobody ever realising that the Doctors are the same person due to the Eighth's current amnesia.