I found this book between very good and excellent. I'm still torn, as I just finished it yesterday.
You get views of McCoy, Kirk, Uhura, and Chekov. Kirk and McCoy are seperated by a different mission than Uhura and Chekov who go off and try and find the missing crewmen. As I'm discovering with L.A. Graf books, there's an affinity to writing about characters who don't get much "screen time" so to speak. The book focuses mainly on Uhura and Chekov's mission and their interaction with the natives whom I found fascinating and three dimensional. The natives are interacting with the crew throughout the book on different levels, not just a "Hey I saw the natives and now they left the story" kind of thing.
Even though McCoy and Kirk have main parts in the book, their story line was more about McCoy and his interactions and discoveries about the mental illness. Kirk played a very small part in the actual story, but I've found this is normal for Graf books.
Uhura and Chekov's mission was probably the better half of the book, though I like Kirk and McCoy a little better. The mission details are in depth and as plausible as possible for this author. It was smooth, even with the changes between the main story lines, and the ending of the Uhura/Chekov was fairly decent.
The wrap up of the whole book was disappointingly unimaginative. It's a pity, but I sort of expected nothing better because the McCoy/Kirk story line was mediocre most of the time and luke warm at best.
It's worth having, especially if you like Chekov, Uhura, or McCoy or are interested in any kind of new species, but not something I'd put on a priority reading list.
If anything, I'm keeping my copy because the cover art is absolutely gorgeous and the best Kirk profile I have seen on a book yet.