The Expanse didn’t initially thrill me, although it’s hard to remember that now, six books later. Leviathan Wakes— the series first book– didn’t really impress me until about a two-thirds of the way through. The first two-thirds followed a boring character (Holden) in an interesting plot arc, and an interesting character (Miller) in a boring arc. But at the beginning of that last third, Holden’s arc and Miller’s arc converge and we finally get to see what sets The Expanse apart from other politically tinged scifi stories: the protomolecule, an extrasolar substance whose origins and purpose I, at least, found highly satisfying– enough to bump the books up to something I would pre-order. There aren’t a lot of books that get that treatment from me.

So it’s reasonable to say that for me, The Expanse is really the story of the protomolecule and its mysterious creators. It’s what hooked me, and while I still enjoy the space battles and political drama and have developed a fondness for quite a few characters in the series (Alex, Amos, Bobbie, and Avasarala in particular), I keep coming back for that mystery. Which is why I was so frustrated when book 5, Nemesis Games, shifted its focus away from the protomolecule mythos and almost exclusively towards intrasystem politics. That Bablyon’s Ashes follows in that vein was less of surprise, given that Nemesis Games end with a vastly shaken status quo. (Spoilers for Nemesis Games and previous books ahead.)

Babylon’s Ashes follows where Nemesis Games more or less leaves off: Belters, the long mistreated inhabitants of the asteroid belt, have grouped up under Marcos Inaros, the charismatic terrorist leader responsible for the devastating attacks on Earth and former lover of Naomi Nagata. The Belters control everything from the belt out, including Medina station and the slow zone linking the protomolecule worlds together. Earth is still teetering on the brink of complete environmental collapse after Inaros’ asteroid bombardments. Mars is crippled by the sudden defection of large chunks of its navy and struggling to put its government back together. The mystery of missing ships bound for other systems is still unanswered. Holden, Naomi, and the rest of the Rocinante crew are docked at Luna for debriefing about their role in the events of Nemesis Games and Inaros’ takeover of the system. (Which amounted to striking the first real blow against Inaros and his Free Navy.)

As bad as things look for Earth and Mars, Inaros’ grip is imperfect. He’s smart and charismatic, but a little unhinged, with a grudge against Earth and Earthers a mile wide and Holden in particular– Naomi, after all, rejected Inaros a second time in Nemesis Games, and there’s no way it’s because he’s a mass murderer, but entirely because Holden stole her– and a hatred of showing weakness that leads to doing extreme things when a potential defeat is looming. When faced with the potential loss of Ceres, the de facto capital of the Belt, for instance, Inaros chooses to strip it of everything valuable and abandon it, forcing Earth and Mars to tie up already thin resources in humanitarian aid– but also alienating millions of Belters. To make matters worse for Inaros, at least on of those alienated Belters is his son by Naomi, Filipe. Filipe’s encounter with Naomi in Nemesis Games had already begun to drive a wedge between him and Inaros, and the once-adoring son is finding himself question Marcos and his actions more and more as time goes on….

Bablyon’s Ashes is a much less frustrating novel Nemesis Games. Book 4, Cibola Burn, ended with some various ominous notes about why the protomolecule civilization vanished and Nemesis Games…just didn’t follow up on it. It wasn’t a bad novel, it was just a disappointing divergence from what I feel is the best part of the series. It’s not as if there were no politics present in the previous books; there was. They’re highly political. It’s more just that Nemesis Games narratively ignored and distanced us from the protomolecule. Bablyon’s Ashes, on the other hand, both brings the protomolecule (somewhat) back into the spotlight and doesn’t represent the abrupt change that Nemesis Games did. The focus is still largely political, but we’re beginning to see how contact with the protomolecule has changed things. Here, armor plating for the Rocinante engineered with techniques learned from the protomolecule; there, a strain of yeast developed with the protomolecule’s ability to feed off of radiation instead of sunlight and thus potentially help feed the crippled Earth.

We also get a couple of better glimpses at what’s coming; the rogue Martian Navy faction has walled themselves off in one of the protomolecule worlds. No one knows what they’re doing, besides supplying Inaros’ Free Navy in exchange for being left alone. There’s another glimpse, possibly, of what killed the protomolecule civilization– the first having come in Nemesis Games, on the very last stinkin’ page. Babylon’s Ashes gives us a glimpse at about the twentieth to the last page, and if we keep that sort of increase, we might see that conflict play out in the next novel or two.

Babylon’s Ashes isn’t the best Expanse novel (That’d be Abaddon’s Gate) but it’s also not the worst.  It kept my interest and had some ultimately satisfying moments. I think there’s a tendency for big series (There are nine planned books) to get bogged down towards the late middle (ala The Wheel of Time), and at the very least, the authors managed to avoid that sort of meaningless meandering that so frequently happens. This isn’t a side story to the real story–no matter what I think the real star of the show is– there’s real change that occurs over the course of these two books. I’d give it a pretty solid B+.