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.
The books resolved most of their existing plots in the first book and the second as well as third felt somewhat one-note. The fourth book, CIBOLA BURN, was really good, though. This book, however, is the start of a three book arc which is just plain awesome. The premise being a radical branch of the OPA, armed with a fleet of Martian warships, attacks the Earth in order to bring an end to its dominion. Its led by protagonist Naomi Nagato's ex-lover and the father of her now-teenage son Filip.
I've always been less interested in the protomolecule and soft science fiction elements of the series versus the politics. The Belter Free Navy are fantastic antagonists, actually villains I'm comfortable saying, with a despicable self-righteousness. They don't care about all the people they kill but portray mass murder of civilians as a victory for freedom. By the end of the book, I wanted them killed more than any other fictional villain than the Freys.
The desperation of our heroes and struggle to deal with the aftermath of the Earth attack works well. The Belters are so full of anger and hatred, many of them celebrate the action. This is something I don't quite buy because after the 9/11 attacks, even many countries which hated America were sympathetic and the Earth assault was a x1000 times worse. I think there would have been many more Belters appalled by the Belter Free Navy's actions.
Part of what makes this book so good is the fact our protagonists are separated for once so we get to see it from multiple perspectives. Amos and Clarissa Mao are on the Earth, dealing with the sudden attacks. Alex is on Mars, trying to deal with the fact he's lost and adrift in his life. Holden is forced to confront the horror of a massive military strike against civilians. Naomi, by contrast, is with the Belter Free Navy as their not-quite-but-effectively-so prisoner.
Marco is a great villain and manages to effectively invoke Che Guevara as well as a lot of other revolutionary leaders. He has a superficial charisma and cloaks all of his actions in revenge, reparations, and a glorious new future while denying the reality of their actions. You can understand why people would follow him while knowing it's not only a cataclysmic mistake but also something that will only result in mass evil being done.
In conclusion, Nemesis Games is probably my favorite of the Expanse novels so far. It's even better than LEVIATHAN WAKES due to the focus on the politics of the setting versus the protomolecule. I'm really looking forward to the sequels and how they deal with such a reprehensible bad guy who has changed the universe through terrorism.