My rating: 3 of 5 stars
Rogue One is a prequel to A New Hope. Catalyst is a filler book tying together the events of Revenge of the Sith movie with Rogue One. I have not yet seen the upcoming movie, but the given what I know from watching the trailers dozens of times, I feel comfortable that I understand where it will be going.
The plot and writing are pretty basic. Books like this name drop a bunch of characters, so we have the expected names like Jyn Erso, the Emperor, Darth Vader, and Moff Tarkin. Plus some extremely minor characters non-fans would need Wookiepedia to recall. Plus some new faces show up.
I liked some of the science introduced in the story. There are some hints that I hope are further expanded in the movie where I can tell my friends, “Well, if you read Catalyst, then you would have seen that coming.”