Leviathan Falls by James S. A. Corey
The final book of the Expanse series focuses on the echoing conflict between the aliens who built the ring space and protomolecule and the entities from a separate universe who destroyed them. In this summary you can see the strength and the weakness of the whole concept around which the novel is built. The concept of the ancient conflict is sweeping and grand and breathtaking in some ways. But the concept is also vague and distant and has to be brought into the present day of the novel in mundane ways that don’t enthrall. The result is a novel that veers between attempting to narrate a conflict vastly older than the human race and outside its scope, and attempting to tie that concept to the present through the vehicle of Duarte, the emerald planet, and the Protomolecule-infected children (and Amos, at the end). All the while bringing this enormous series of novels to a conclusion that still keeps faith with the central core of characters, including Holden, Naomi, Amos, and the rest, with whom we’ve made this whole journey. When it’s described this way, the novel is amazingly successful. During the reading, though, it falters, sometimes flailing from one conceptual framework to another, insisting at last on the agency of Holden at the helm of the Ring station to bring it all together, save the day, and destroy what’s left of the protomolecule builders and their network of gates. Since we never entirely understand the nature of the old conflict or the terms in which to read it, that side of the novel and series is unsatisfying. On the other hand, the human conflict, the fall of Laconia, and the end of Duarte, are very strong. I found myself liking the whole series very much after I no longer had to read it. The achievement of the books is actually epic, especially given the failure of so many other multi-novel series even to reach a conclusion at all.