NEMESIS GAMES is the fifth book in the Expanse series, which is about humanity 200 years in the future when we've managed to colonize the rest of the solar system. Humanity is divided into Earthlings, Martians, and Belters with varying degrees of oppression. A mysterious alien object called the protomolecule has changed the balance of power between them and opened up new possibilities to visit other star systems.
CIBOLA BURN is the fourth novel of the Expanse series which I've very much enjoyed even if I've stated my preference for the TV adaptation. The Expanse's premise is it's about two hundred years in the future and humanity has not changed a bit. The rich abuse the poor, there's racial caste systems, and governments are either greedy or oppressive (or both). The first few novels were very hard science fiction but have shifted a bit with the introduction of ancient alien technology.
ABADDON'S GATE is the third volume of the Expanse and while it promises many new and interesting developments, isn't one I enjoyed as much as the previous installments. That's not to say the novel isn't good but it has some flaws which made me think this series might be running out of steam. I hope I'm going to be proven wrong but the only way I can do that is to pick up the next volume.