The new threat is the Swarm. They are zombies, but a little different than the zombies of the Walking Dead. The Swarm can speak, and think, but the goal is pretty much the same. The Swarm will bite you, infect you and turn you into one of them.
Pepper crash lands on Chilo and warns the people that the Swarm is coming.
Sly Mongoose is the third book of Tobias S. Buckell‘s Xenowealth series. I enjoyed Crystal Rain and Ragamuffin a great deal, but I felt Sly Mongoose was a major improvement. I’m guessing Buckell had a better grasp on the craft, or least the series, when he went to work on Sly Mongoose.
The writing is very good, easy to read, an excellent flow. The world building dazzled me and the scenes were interesting. I’m not saying Crystal Rain and Ragamuffin didn’t have all that, but I feel it’s better done in Sly Mongoose.
If I was to rank the three Xenowealth books that I’ve read, I’d say that although I enjoyed Ragamuffin, I didn’t like it as much as Crystal Rain, and I liked Sly Mongoose far more than I liked Crystal Rain. Even so, I recommend you start the series with the first book and work your way through. It’s action-packed science fiction and it’s fun.