As others have said, this starts off pretty slow. The four major characters are split up in the beginning, and each has its own story arc. Eventually, the larger story going on ties it all together. Things do pick up in the second half of the book.

The Expanse series is built in trilogies. Just like Caliban's War set up a major change moving into the third book, Nemesis Games sets up a major change moving into the final part of this trilogy. We also get the return of several interesting characters from previous books. I hope that we will continue to see more of them in the next one.