by YetAnotherMovieWatcher - Is this helpful?
The Expanse is an adaptation of a series of novels by James S. A. Corey, the pen name of the two authors who co-write the book series.
This series adheres to the books quite well, though it isn't one-novel-per-episode, more like one novel per season.
All of that aside, this is an excellent series. The characters are believable in their setting of a mostly-corporate-controlled future. The pacing is a bit iffy in the first few episodes, but by and large it isn't a problem and it does get better a few episodes in.
The setting is this:
There's Earth, whose government is torn with some seeking to control or best the government of Mars and the emerging government of the Belt.
There's Mars, who consider themselves pretty autonomous (and they are), and who are bent upon a generations-long project to terraform Mars so that men don't have to live under domes.
There's the Belt, which basically includes people in the asteroid belt and beyond.
If that amount of political upheaval isn't enough, something new is coming...