The Mercy of Gods is the first volume of The Captive’s War, a new series from the author of the wildly successful The Expanse (2011-2022). That series (both books and television adaptation) managed to raise the stakes with every installment while making each feel satisfyingly self-contained. I still have not finished the final volume, for instance, and so don’t know how that series ends—and perhaps that ability to read just one or to stop at any point is an issue the publisher hopes Corey can address with this new book. Unlike the first volume of The Expanse, The Mercy of Gods feels like a long set-up rather than a novel that stands on its own two feet.

Anjiin is a world settled by humanity thousands of years ago. Knowledge of Earth has been lost, but it’s clear to the human inhabitants that they came from elsewhere and are not part of the native biome. (For anyone looking to connect this to the universe of The Expanse, Anjiin could easily be one of the many worlds settled through the “gates” at the end of the third volume.) Despite time and cultural distance, however, Anjiin is basically an Earth-analogue. The buildings are grown from coral, but the planet’s humans form research academies, drink coffee, eat sandwiches, and have no technology significantly advanced beyond today’s. It feels like Corey wants the stakes of an alien invasion without putting Earth in the crosshairs.

Within the first third of the book, Anjiin has been invaded and its habitants enslaved by aliens known as the Carryx, a race that has built a galactic empire subjugating and domesticating hundreds of other intelligent lifeforms. Any species that proves useful survives to serve; if it does not, the species is culled. The Carryx transport the best and brightest from Anjiin to their home planet, and this is where the plot begins in earnest, following a team of research biologists charged with finding a way for different species to communicate biochemically. This is where Corey excels: As with the crew of the Rocinante in The Expanse, Corey creates a cast of likeable characters with friendships and rivalries that feel real and compelling.

Corey also succeeds in providing significant interiority here. For example, one of the main characters, Jessyn, deals with severe depression and suicidal ideation, which she controls with medication. One thread of the plot involves Jessyn sliding back into depression and the team working to synthesize the necessary drugs for her treatment. The view from inside Jessyn’s head gives readers a sympathetic look at what it might be like to build a career and cope with clinical depression—and yet always live in fear that could slip away. That Corey succeeds in drawing this minor arc against the background of planetary subjugation shows his skill as a crafter of characters.

In this way, Corey puts together a team of scientists who care about each other and makes the reader care about them—and then plunges them into the midst of a system they can’t understand. Imprisoned in the depths of the Carryx world-palace, they don’t understand the way their captors work or how to succeed at the tasks they have been given. Over and over, attempts to make sense of their situation fail:

Whatever it looked like, it might be something else. (p. 136)

No matter what conclusion you drew . . . you’d made a mistake. (p. 139)

Only Dafyd—a benign, easygoing lab assistant who becomes the book’s main protagonist—is able to accept that the only route to long-term survival lies not in rebellion or reasoning but convincing the Carryx of their usefulness.

Dafyd, according to the short testimonials peppering the book which seem to hail from a point of view in the future, will become humanity’s savior and betrayer. In his role of an everyman with sound insights into how the Carryx do business, he’s a strong echo of the main protagonist of The Expanse. Unlike his colleague Jessyn, though, Dafyd remains fairly flat and undeveloped throughout the novel, with the reader’s view of him shaped by legends that apparently build up around him later, figuring him much like a Paul Atreides to a Muad’dib. The comparison is especially apt because the volume’s dedication is to Ursula Le Guin and Frank Herbert, acknowledged by Corey as “teachers … never met.” There is certainly a sense of galactic tragedy here akin to Dune (1965), underscored in those testimonials that start each section of the book and which anticipate Dafyd’s ultimate role:

The betrayer … could dream of perfection without being fettered by it. He desired peace and destroyed countless worlds to take it. He held both these ideas in his mind at the same time, and instead of this dissonance ripping him apart, it made him powerful. If we had known that before it was too late we would have killed him. You should take note of that.

You would be wise to kill him too.

—From the final statement of Ekur-Tkalal, keeper-librarian of the human moiety of the Carryx (p. 148) 

Yet this is all anticipation. There was only one relationship developed in the novel that could have made Dafyd feel like the betrayer he’s foreshadowed to become, and Dafyd didn’t betray it. The swarm, a nano-particle parasite sent to Anjiin before the invasion by an enemy of the Carryx, takes over the body of Else, the woman Dafyd loves, early in the novel. For the bulk of the narrative, Dafyd doesn’t realize he’s having a relationship with an alien weapon sent to spy on the Carryx. Ultimately the sentient swarm discloses its true nature in an attempt to convince Dafyd to reveal to the Carryx a human rebellion that might otherwise end the swarm’s mission. This is where I anticipated Dafyd’s ultimate betrayal would come: that he would sacrifice not the human rebellion but what he believed was the woman he loved—and also the only real weapon against the Carryx—to prove that humans could be useful to their new alien overlords. That would have been a wrenching betrayal to make readers hate Dafyd as much as we’re told he’s eventually hated by his descendants. But instead, Dafyd betrays that small human rebellion composed of secondary characters, something minor enough that we’re left wondering what the big deal was. This novel doesn’t help readers feel any significant stakes of this particular betrayal.

The Mercy of Gods has all the readability that rightfully made The Expanse so successful. If you’re looking to get invested in another epic sci-fi series and its cast of likeable characters and don’t mind having many more questions posed than resolved (or if you simply wished there were more aliens in The Expanse) then this is the book for you. But treat it as the first season, or perhaps rather the pilot episodes, of a compelling Netflix series. A major theme in The Mercy of Gods is the unknowability of the universe. Don’t look for closure or a complete arc in this first volume—rather seek set-up for what’s to come.