I'm going to have to disagree with the previous reviewer. Obviously, "Operation: Annihilate!" is a re-telling of the classic episode of the same title. While there aren't a lot of changes, they did do some things different, including creating a more edgy relationship between Kirk and his brother as a result of their father being dead. I won't say any more so as not to spoil anything, but this did change things a bit. Meanwhile, the second story in the book isn't even based on an Star Trek episode. I know, I have them all on DVD. The plot stems from events that happened in the most recent movie that never happened in the "regular" Star Trek universe. So, it can't possibly be a re-used story. So, when the previous reviewer said they are simply taking episodes and making slight changes, it wasn't true.
All in all, I found this to be a good book. I'm not sure if it's worth the $17.99 list price, but it costs a lot less for the Kindle and even the paperback is reduced here, so no worries. (Star Trek graphic novels are usually overpriced, just like Star Wars graphic novels.)