A Reaper at the Gates recap

The Nightbringer, holding the last fragment of the Star, works toward freeing the jinn imprisoned beneath the Waiting Place, while Keris Veturia plans both the extermination of the Scholars and the seizure of the throne. Laia travels north to Adisa seeking a weapon or an ally against him, finds neither in the Mariner court but gains the Scholar spymaster Musa. Elias, bound to the Waiting Place, cannot make its magic answer him while he still loves anyone living. The Blood Shrike is sent to Navium, where Keris lets the city burn under a Karkaun assault to discredit her; Helene saves it and cannot prove the sabotage. The Karkauns then besiege Antium, Keris withdraws her legions, and the capital falls. Keris executes most of Helene's family, Marcus dies, and Keris takes the throne as Empress. Helene escapes with her sister Livia and Livia's newborn son, whom she declares Emperor. Laia discovers that the woman called Cook is her own mother. Shaeva dies, Elias surrenders his humanity to become the Soul Catcher in full, and the Nightbringer completes the Star and releases the jinn.

Previously: Laia, a Scholar of the Martial Empire, lost her grandparents and her brother Darin to a Martial raid and went into Blackcliff Military Academy as a slave in exchange for the resistance's promise to free him. There she met Elias Veturius, the Academy's best student and the unacknowledged son of its commandant Keris Veturia, who was forced by the Empire's Augurs to compete in Trials for the vacant throne. Marcus Farrar won the Trials by killing his twin brother; Elias's closest friend Helene Aquilla refused to kill Elias and was bound to Marcus as his Blood Shrike; Elias was condemned and broken out by Laia. Laia, Elias, the slave girl Izzi and the resistance fighter Keenan fled north to Kauf prison to free Darin. Elias was dying of poison the whole way. They burned Kauf and freed its prisoners, Izzi was killed, and Helene, sent to hunt Elias, let him go instead. To save his life the jinn Shaeva bound Elias to the Waiting Place, the forest where the dead pass on and where the jinn are imprisoned, which means he can never leave it. Then Keenan asked Laia for her mother's silver armlet as a token of trust, and once she gave it he revealed himself as the Nightbringer, the last free jinn, who had spent a thousand years collecting the fragments of an object called the Star in order to free his people.

The Nightbringer holds the last piece of the Star and moves openly through the Empire, allied with Keris Veturia, whose plans for the Scholars amount to their extermination. Laia, travelling with her brother Darin and the old Blackcliff kitchen woman known as Cook, is hunting for anything that can kill a creature a thousand years old, and finding that her ability to vanish now fails at the worst moments. Elias is learning the Soul Catcher's work under Shaeva in the Waiting Place: shepherding ghosts onward before their grief makes them dangerous, and keeping the jinn behind the walls of their prison. The magic that should carry him will not, because it demands a distance from the living that he refuses. In the capital, the Emperor Marcus is unravelling and the Empire is losing ground to Karkaun raiders in the north. The Blood Shrike is sent south to Navium, Keris's own city, to bring its fleet and its great houses to heel.

Navium is Keris's power base, and every Martial with rank there answers to her rather than to the Emperor's Blood Shrike. When a Karkaun fleet appears off the harbour, Keris keeps her ships in dock and lets the city's poorest districts burn, so that the failure will be recorded as Helene's. Helene takes command of what she can, holds the sea wall, and discovers that her healing song is stronger and stranger than she understood. Avitas Harper stands with her without being asked. Elsewhere, Shaeva warns Elias that the jinn are pressing at their prison and that if it breaks, the Waiting Place fails and every restless ghost in the Empire goes with it. Laia leaves the Empire for the free kingdom of Marinn in the north, taking Darin, hoping the Mariners and the Scholars sheltering there can be persuaded to act against the Nightbringer.

The fight for Navium becomes a siege by sea. Helene fights it with borrowed ships and Blackcliff tactics, and Keris sabotages her at every step while remaining technically obedient. Helene finds evidence that the Karkaun warlocks are being supplied with a magic no human should have and that the Commandant's ally is not a person at all, but nothing she can put before a court. In Adisa, Laia's petition to the Mariner court goes nowhere: the heir Nikla will not risk a war with the Martials for the sake of Scholar refugees, and the Scholar community in the city is fractured. Laia instead finds Musa of Adisa, a Scholar who runs a private intelligence network of invisible wights and knows everything happening in the north. Cook's knowledge of the Empire's secrets continues to be inexplicable for a woman who spent her life in a kitchen.

Navium survives, at a cost that empties the city's treasury and its cemeteries, and Helene breaks the Karkaun fleet without ever being able to prove who arranged the disaster. She returns north knowing that Keris has been building toward the throne for years and that the Karkaun warlord Grimarr is being fed intelligence and supplies from inside the Empire. In Marinn, Laia's position collapses: the court turns on the Scholars, Darin's knowledge of steelmaking makes him a prize rather than a person, and Laia and Musa are forced out of Adisa with almost nothing gained. Elias, meanwhile, is told by Shaeva what the magic actually requires. Mauth, the power that runs through the Soul Catcher, will not fully bind to anyone who still holds on to a living person, and the ghosts are multiplying faster than one apprentice can move them.

The action moves to Antium, the Martial capital. Marcus's grip on himself is nearly gone, Livia is close to term with the imperial heir, and Keris manoeuvres in open court, calculating exactly how much humiliation the Blood Shrike will absorb before she breaks. Helene, with the support of Elias's grandfather Quin Veturius, tries to build a faction that can survive the Commandant. Laia returns south into the Empire, and she and the Blood Shrike, who have every reason to hate each other, are forced into a working arrangement against a threat that will outlast both their causes. The Nightbringer no longer bothers to hide, and the Scholar settlements in the Empire begin to be emptied on the Commandant's orders.

In the Waiting Place, the jinn's prison is failing and the ghosts have become a flood. Shaeva is killed, and Elias is left as the only thing standing between the dead and the world, with a magic that still will not answer him. He tries to hold the forest alone and cannot. Laia's search for a way to stop the Nightbringer keeps arriving at the same answer: the jinn were imprisoned by a Scholar working with one of their own, and there is no second Shaeva to repeat the trick. Keris positions her legions where they will do the Empire the least good, the Karkaun host under Grimarr crosses into the Martial heartland, and Antium is left with walls, a failing Emperor and a Blood Shrike who can see precisely what is about to happen and cannot make anyone believe her in time.

The Karkauns lay siege to Antium. Keris withdraws her legions and leaves the capital to hold with what it has, which is not enough. The walls are breached, the warlocks work over the city, and the slaughter inside it is comprehensive. Helene fights through the streets to reach her family and her sister, using her healing magic until it nearly kills her, and holds a corridor open long enough for part of the population to escape. Livia goes into labour during the fall of the city. Laia is inside Antium as it burns, and what she can do against jinn magic is very little. Every institution the Empire has run on for five hundred years is destroyed in the space of a few days, and the survivors are left arguing about who is now entitled to command them.

Antium is lost. In the wreckage Keris has Helene's father and her sister Hannah executed in front of her; House Aquilla is destroyed apart from Livia, who has borne a son. Marcus dies, and Keris Veturia declares herself Empress of the Martial Empire. Helene gets Livia and the newborn out of the city with the legions still loyal to her. Laia learns who Cook is: her own mother, Mirra, the Lioness who led the Scholar resistance a generation ago and was believed dead, kept alive and broken by the Commandant. The Nightbringer, meanwhile, has everything he needs. Laia's attempt to stop him at the Waiting Place fails, and Elias, holding the forest alone since Shaeva's death, is given Mauth's terms: the magic will serve him only when he has cut away every living attachment he has.

Helene declares the infant Zacharias Emperor of the Martial Empire, with Livia as his regent, and withdraws north to Delphinium to hold what is left against Keris. The Empire now has two rulers and a civil war. Elias accepts Mauth's terms: he sends Laia away, severs what he feels for her and for everyone else, and takes on the Soul Catcher's mantle completely, which is the last thing Elias Veturius does as himself. And it is too late. The Nightbringer completes the Star, breaks the prison beneath the Waiting Place and frees the jinn, who greet him as the Meherya, the beloved. A thousand years of confinement come out with them, and the human kingdoms have nothing that can answer it.

Antium falls to the Karkauns because Keris Veturia withdraws her legions and lets it happen. In the ruin of the capital she has Helene's father and her sister Hannah killed in front of her, destroying House Aquilla except for Livia, who gives birth to a son during the siege. Marcus dies, and Keris declares herself Empress of the Martial Empire. Helene names the infant Zacharias Emperor, takes him and Livia out of the city with the legions still loyal to her, and withdraws north to Delphinium to fight a civil war she is not equipped to win. Laia learns that Cook is her mother, Mirra, the Lioness who led the Scholar resistance and was assumed dead for years. In the Waiting Place, Shaeva is gone and Elias is left holding the ghosts and the jinn's prison alone. Mauth, the power behind the Soul Catcher's work, will only serve him if he severs every human tie he has; he accepts the terms, sends Laia away and stops being Elias Veturius in any way that matters. It is not enough. The Nightbringer completes the Star, breaks the prison and frees the jinn, and his own kind name him the Meherya, the beloved. The Empire is left with two claimants, an unbound and vengeful jinn host, and no one who can stop them.