There are a few quibbles that I have with this book, most notably that it's difficult to place it on the Star Trek timeline. The intro by the author says that it is a story that arose out of the same brainstorming sessions that produced the movie "Star Trek IV: The Voyage Home", which would suggest a similar time-frame. But that concept clearly doesn't work, as the events in the second and particularly the third Star Trek movies have obviously not happened (notably, the death and return of Spock and the destruction of the Enterprise). Thus, given those facts and a few hints toward the end of the book, it seems likely that it takes place between movie #1 (Star Trek: The Motion Picture") and movie #2 (Star Trek: The Wrath Of Khan"). It would have helped if that had been made a little clearer a little earlier, but truly, this is a minor quibble.
The problem is, the book itself isn't really good enough to cause one to be willing to overlook minor quibbles. It isn't terrible; the writing is fairly good, the characters recognizable as themselves, the dialogue plausible, the minor characters from the Enterprise and the missing science team interesting enough. But the characters that the Enterprise crew must interact with range from vanilla personalities with no real spark to stock villains with no real spark. And the plot itself, while not without promise, never fulfills that promise. There was never really any sense of drama, never any sense of compelling interest. It was, quite honestly, mediocre.
If you're a Trek fan with a real need for a fix, there's no reason not to read this one; it's a perfectly acceptable read. But if you aren't desperate for a Trek story, there's no particularly driving reason TO read it, either.