""The Destroyer" assignment had come about when Murray, editing "Skullduggery", sought out Murphy and "The Destroyer" co-creator Richard Sapir for an interview, and later doing freelance research for Sapir.This led to his editing a Destroyer sourcebook, "The Assassin's Handbook" (1982) and eventually ghostwriting the series, beginning with the 56th book, "Encounter Group" (1984).