Nick Carter-Killmaster is a series of spy adventures published from 1964 until the late 1990s, first by Award Books, then by Ace Books, and finally by Jove Books. At least 261 novels were published. No actual author is credited for the books, with the "Nick Carter" name being used as a house pseudonym. Volumes varied between first person and third person narrative. Two authors known to have contributed entries in the series are Michael Avallone and Valerie Moolman