Instruments of Darkness is a BBC Books original novel written by Gary Russell and based on the long-running British science fiction television series Doctor Who. It features the Sixth Doctor and Mel.This novel concludes a trilogy concerning the Pale Man and the Irish Twins which began in Russell's The Scales of Injustice and Business Unusual. Evelyn Smythe, the Sixth Doctor's companion from the Big Finish Productions audio plays, also appears.