Abaddon's Gate

The Expanse continues to strike a really good middle ground on lots of issues. The books are long enough that plenty happens, but are mostly dialogue so they aren't as big as the page count implies. If you've ever read a long book and thought “there wasn't enough plot for this many pages,” the Expanse is NOT like that.

The tone is serious enough that there are real stakes to the point that it feels like main characters are in authentic danger, but not just arbitrarily killing off everyone.

It's more fun than most “serious” books, but a lot more thoughtful and intrigue-ful than most “fun” books.

I'm only 3 books in, but it's a long series and it's impressive that they still have lots of new ideas and don't feel redundant.

The science is very well-considered and they clearly talked to some physics people to be sure they understood how travel and logistics work in zero gravity. And if we find alien life, it's almost certainly not going to be humans with a small twist (blue skin, etc), but will likely be something so strange we can't even tell what it is. This continues to include the strangeness of the alien life, and how our response to it is likely to be an uneasy combination of confused and conflicting scientific, political, and military wrangling.

I also really appreciated the presence and posture of the religious people. The Expanse does a great job in general of not treating any group as a monolith, so the religious crowd is a mixture of pious and sleazy, established traditions and start ups. But no one is a caricature, and the main pastor's grasp of a central Christian belief - no one is beyond redemption - is handled extremely well in service of a plot line. That's rare enough in fiction generally, but especially in sci-fi/fantasy, and I salute them. (Maybe see Speaker for the Dead or The Sparrow for other examples)