I know a good plot when I see one and this plot came almost up to par, but not quite.
The planet The Enterprise is investigating itself is very well constructed and thought out, bringing the creatures to life like many other books (including Star Trek books) sometimes don't. Of the three species, only two are really thoroughly explained which was a bit of a disappointment, but I understand it was more about getting to the plot than adding a page more about the third species.
I am a fan of McCoy, and seeing him in command in a job Kirk does every day was quite humorous. Of course, he brings his own quirky personality, but in the end acts more like Jim Kirk than McCoy which I wasn't sure I liked or disliked. I thought he could have been more three dimensional in that aspect instead of everyone defaulting to the famous James T. Kirk.
But that's really a minor issue. The major issue I have with this book is the flow. It flows well the first third or so, chops a little in the middle, and has a tidal wave chop towards the end. Everything ended so quickly, it felt like the author ran out of allotted pages. Major issues in the plot were filled in hastily and sloppily.
Despite those flaws, it's quite a fascinating read. I wouldn't pay more than 3 dollars or so for it with free shipping quite honestly, but I am fond of it even if I wasn't totally satisfied with the execution of the plot. Intriguing for a biologist such as myself.
As I read more and more of the old Star Trek books, I have come to realize that anything written by Diane Duane is going to be a winner. This book is no exception. She is able to present the family aspect of the Enterprise crew much better than most. In this story, the command structure is much more apparent than in other stories, due largely in part by the plot device of leaving McCoy in command of the Enterprise. The Doctor handles it well and with good humor. As with Duane's other Star Trek books, linguistics plays a significant role in the story line. I really should read some of her non-commissioned work.
One of the funnier Star Trek novels with "Captain" Dr. McCoy in charge, anything (and everything) is liable to happen (and it does!)
When Dr. McCoy grumbles once too often about the way the Enterprise ought to be run, Captain Kirk decides to leave the doctor in command while he oversees a rountine diplomatic mission. Kirk beams down to a strange planet nicknamed Flyspeck to negotiate its admission into the Federation, leaving Dr. McCoy to enjoy his new authority. However, the doctor soon learns that command is a double-edged sword when Kirk disappears without a trace. Desperately trying to locate his catain, McCoy comes under pressure from Starfleet to resolve the situation immediately. Matters go from bad to worsewhen the Klingons arrive and stake their own claim on Flyspeck. Then another, more deadly power threatens them all, and suddenly Dr. McCoy and the Starship Enterprise find themselves pitted against an alien fleet in a battle they have no hope of winning.