More substantial was the Matt Helm series, published by Gold Medal, which began with "Death of a Citizen" in 1960 and ran for 27 books, ending in 1993 with "The Damagers". Helm, a wartime agent in a secret agency that specialized in assassinating Nazis, is drawn back, after 15 years as a civilian, into a post-war world of espionage and assassination. He narrates his adventures in a brisk, matter-of-fact tone with an occasional undertone of deadpan humor. He describes gunfights, knife fights, torture, and (off-stage) sexual conquests with a carefully maintained professional detachment, like a pathologist dictating an autopsy report or a police officer describing an investigation. Over the course of the series, this detachment comes to define Helm's character. He is a professional doing a job; the job is killing people. Hamilton completed one more Matt Helm novel, "The Dominators" in 2002, that has not been published.