Time was Star Trek books were very different from what fans have known for the past 37 years. The novels were not carefully reviewed by Paramount licensing for accuracy and continuity. They were not written by people who were Star Trek fans and knew every episode by heart. They were science fiction novels by professional science fiction authors who had no previous tie to the series, and the stories they produced bore little resemblance to the TV show whose title graced the books’ covers.
In April, 1976, when Jean Lorrah first published Night of the Twin Moons, there had been only a single original Star Trek novel published. It was Spock Must Die! By James Blish, the veteran SF author who had thus far novelized 71 episodes of the original series, making Trek the first TV series in history to have (almost) all of its episodes turned into prose stories. (Blish never novelized the Kirk-era parts of “The Menagerie,” although he did novelize the original pilot episode, “The Cage.”)