The story iis about how the crew of the Enterprise spend their time after the completation of the five year mission. Kirk became an Admiral, Spock takes a teaching position on Vulcan ans ends up meeting a female Vulcan and becomes engaged. And McCoy well he ends up getting into some trouble and needs both Kirk and and Spock to get him out of it.
This was actually an enjoyable read. If you're Trekkie you should try to get a copy. 4/5