Over the course of eight books, The Expanse has felt a bit like one of those videos that zooms out from Earth into the larger universe. Part of the appeal of Leviathan Wakes and Caliban’s War was that they were a space opera set in our local neighborhood, dealing with issues that are relevant to the world we now live in: war, racism, justice, all accompanied by power armored-marines, spaceship battles, and a menacing alien threat.

But as the series progressed, authors Daniel Abraham and Ty Franck (collectively known as James S.A. Corey) have, well, expanded their scope to more cosmic issues. Abaddon’s Gate opened up the cosmos to humanity by way of an alien, ring-gate system; Cibola Burn introduced us to a brand-new planet; 2017’s Persepolis Rising kicked off the endgame for the series; and the latest and penultimate installment of the series, Tiamat’s Wrath, rockets us closer to what promises to be a tumultuous end for the crew of the Rocinante as they face challenges from old enemies and new threats.

Some spoilers ahead for the novel and parts of the series.

Image: Orbit Books

Persepolis Rising jumped the story of The Expanse three decades forward. Humanity had largely put aside some divisive issues and begun colonizing the galaxy via a system of ring gates. That progress was put on pause when a rogue faction of Martian separatists reemerged from their self-imposed exile on their colonial world Laconia. They’d spent that 30 years quickly advancing with the help of an alien substance known as the protomolecule — the remaining bit of technology left behind by a long-dead alien species that kicked off the events of the series. Laconia’s leader, Winston Duarte, was made immortal by some of those advances. And he had some lofty goals for humanity: he proclaimed himself to be the High Consul of the Laconian Empire, promptly took control of our home solar system, and established a new regime to oversee the colonized systems. The crew of the Rocinante and their allies were left scattered, unsure about how to overtake this new, seemingly insurmountable threat.

Tiamat’s Wrath picks up that story and runs with it. Captain James Holden has been captured and imprisoned on Laconia, Naomi Nagata is hiding in shipping containers trying to coordinate a resistance, former Martian Marine Bobbie Draper and pilot Alex Kamal are plotting strikes against Laconian forces, and mechanic Amos Burton is missing in action. Like the other installments of The Expanse, the book jumps from perspective to perspective. It delivers the various viewpoints of the crew as they work to resist the Laconians, but it also follows members of the Empire — like Elvi Okoye (last seen in Cibola Burn), who’s undertaking critical science missions for Duarte, and the emperor’s daughter Teresa, who is growing up and learning how the Empire runs. With the end of the series fast approaching, the stakes are getting raised, and Corey makes it clear that nobody is safe: a couple of fan-favorite characters meet their end, one in the very first line of the novel.

A running theme throughout the entire Expanse series has been how people deal with technologies that are far beyond their understanding, and as Duarte has worked to grow humanity into a galaxy-spanning civilization, a major source of concern is the ultimate fate of the gate-builders. They had seeded the galaxy with their technology, only to be mysteriously wiped out by an unknown presence, which made itself known at the end of Persepolis Rising.

Duarte dispatched Elvi on a scientific mission to better understand what they’re up against, exploring fantastically strange solar systems. They make some awe-inspiring discoveries: a star-sized diamond in one system might be a data storage artifact, while another system contains a white dwarf, just on the brink of collapsing into a black hole. Elvi discovers that her mission isn’t just exploration and discovery; Duarte wants to go toe to toe with that mysterious presence, to see if it can be reasoned or negotiated with. Duarte explains a version of the scenario to his daughter, Teresa: the prisoner’s dilemma, where the two parties’ goals will eventually line up if given enough tries.

But these ancient, mysterious aliens aren’t the only threat to the Laconian Empire. Naomi, Bobbie, and Alex take part in a resistance movement against their forces. It’s a huge challenge: the Laconians are technologically superior, with ships that wield awesome and terrible destructive power, and which also can heal themselves after battle. They have an iron-clad grip over the thousands of worlds held by humanity, and while Duarte leaves the impression that his rule is a benevolent one, the reality is far more cruel. His forces are set to crush any dissenters while controlling the flow of information, and he’s willing to sacrifice entire systems in the name of his experiments.

Corey’s series has always touched on the state of the worlds, providing a sort of commentary for how humanity can get through troubled times by cooperating across political and racial lines, and Tiamat’s Wrath is no exception. The book is a solid argument for the need for people to act against tyranny and oppression in any way possible, standing up for what’s morally right.

One passage stuck out for me as I was reading: an exchange between Naomi and another crew member named Emma, who sums up the problem of Laconia’s top-down approach: humans simply don’t work well with hugely oppressive structures governing them.

“Easy to make systems with a perfect logic and rigor. All you need to do is leave out the mercy, yeah? Then when you put people into it and they get chewed to nothing, it’s the person’s fault. Not the rules. Everything we do that’s worth shit, we’ve done with people. .... Laconians making the same mistake as ever. Our rules are good, and they’d work perfectly if it were only a different species.”

A dominant theme of the series has been the limits of humanity, and that line of reasoning is on display here. People have a hard time living in the depths of space or on planets that aren’t Earth; we have trouble with comprehending the vast distances of space, and the capabilities of the beings that created the vast artifacts scattered on dead worlds; and when someone tries to change themselves into, say, an immortal god-emperor for all of humanity, something vital is lost. It invites serious threats to humanity as a whole — whether that’s tribal divisions from things like racism and warfare, or an ancient, unknowable alien threat that doesn’t like how we’ve been poking it with explosives... and decides to hit back.