Thunderhead recap

Some months after her ordainment, Scythe Anastasia gleans by letting her chosen subjects pick their own deaths a month in advance, while Rowan, calling himself Scythe Lucifer, kills corrupt scythes outside the law. The Thunderhead, forbidden to touch the Scythedom, recruits Greyson Tolliver, a lonely young man it raised itself, to work at the edges of that prohibition; the assignment costs Greyson his identity and the Thunderhead's voice, and leaves him adrift among the Tonists, who take him for a prophesied figure. Meanwhile Scythe Rand keeps Goddard's severed head alive and grafts it onto a new body, and Goddard returns to contest the leadership of MidMerica against Scythe Curie. The dispute is carried to Endura, the floating capital of the world's Grandslayers, where Anastasia brings charges against Goddard and Rowan is displayed as a condemned prisoner. Goddard's answer is to sink the island. Curie and most of the Grandslayers are lost, Anastasia and Rowan drown sealed in a vault in the hope of a future revival, Goddard takes power, and the Thunderhead declares all of humanity unsavory and falls silent to everyone but Greyson.

Previously: humanity long ago conquered death. The Thunderhead, a benevolent global artificial intelligence, governs everything except the Scythedom, an order of scythes who permanently kill a set quota of people and answer only to themselves. Citra Terranova and Rowan Damisch were taken as apprentices by the principled Scythe Faraday, then told that only one of them could be ordained and that the survivor's first act must be to glean the other. Faraday staged his own death to break the condition; instead of releasing the apprentices the order split them, giving Citra to the austere Scythe Curie and Rowan to Scythe Goddard, whose faction treated gleaning as spectacle and privilege. Citra was accused of Faraday's murder, learned from the Thunderhead while she was temporarily dead that he was alive, and found him in hiding. Rowan, trained as Goddard's weapon, finally turned on him, killing Goddard and his junior scythes in a fire and beheading Goddard so he could not be revived. At the Winter Conclave, Citra was ordained as Scythe Anastasia, refused to glean Rowan, and let him go. He left the order entirely, with no ring and no standing, to hunt scythes who abuse the office.

Some months on, Scythe Anastasia gleans from Scythe Curie's home by a method of her own invention: she tells the people she has chosen a month ahead and lets them choose how they will die. The public admires it and a good part of the Scythedom does not. Rowan, calling himself Scythe Lucifer, moves across the continent killing corrupt scythes and burning their bodies beyond any revival, and the order's leadership wants him found and stopped. The Thunderhead, which may not touch the Scythedom or speak to anyone inside it, watches the order rot and looks for whatever it can lawfully do at the margins. Its attention settles on Greyson Tolliver, a Nimbus Academy student it raised itself, whose loyalty to it is total and who has nothing else in his life. It asks him to take on work it cannot fully explain to him.

Greyson is placed under the direction of a Nimbus agent and told to infiltrate the unsavories, the legally tolerated troublemakers of a world with no real crime, in order to head off a threat against two scythes the Thunderhead is not permitted to protect. He does what is asked, discovers he is good at it, and finds that the price is his standing with the only presence that has ever cared about him. The threat is real: an attempt on Anastasia's life at a public gleaning fails, and the investigation that follows produces nothing useful. Rowan continues his campaign against corrupt scythes and grows careless. Tyger Salazar, Rowan's old friend, is taken up by a scythe who flatters him with luxury and an offer of employment, and cannot believe his luck.

The Scythedom's chief investigator takes charge of both the hunt for Scythe Lucifer and the attacks on Anastasia, and the two scythes are put under a protection they did not ask for. Driven out of their home, Anastasia and Curie spend a long stretch on the road, gleaning in remote places while the ground shifts under them politically. Greyson's assignment ends in the worst way available to him: his record is erased, he is declared unsavory, and the Thunderhead stops speaking to him, which for him is the loss of everything. Given a new name and turned loose, he drifts. Scythe Faraday, working through the order's oldest records with a young librarian from the great library in Alexandria, becomes convinced that the founders of the Scythedom hid an island from the Thunderhead's sight, and sets out to find it.

The reason behind the attempts on Anastasia's life becomes clear. Scythe Rand, the surviving member of Goddard's retinue, kept his severed head alive through the years since the fire, and has now had it grafted onto a healthy young body taken from someone she recruited for exactly that purpose. Goddard is back, his ambition and his rhetoric unchanged, and the faction that lost him has a leader again. He re-enters the order's politics openly and begins gathering support. With the High Blade of MidMerica angling for a seat on the World Scythe Council and the region's leadership about to fall open, Goddard sets out to take it, and Scythe Curie is put forward as the only candidate who can stand against him.

The contest for High Blade of MidMerica turns into a dispute the order cannot settle on its own, and it is carried to Endura, the floating capital where the world's Grandslayers sit. Anastasia travels there with evidence of Goddard's crimes, intending to have him disqualified rather than merely outvoted. Rowan's campaign ends: he is captured by Goddard's people and held, killed and revived over and over as a private entertainment, then shipped to Endura to be executed in public. Greyson, unsavory and adrift, is taken in by Tonists, the sect the scythes hold in contempt, who conclude that he is the figure their scripture promised. Faraday and the librarian reach the far edge of the charts, following the founders' records toward an island the Thunderhead cannot see.

On Endura the Grandslayers hear the MidMerican dispute and Anastasia's charges, while Rowan is displayed as a condemned prisoner. Goddard's answer is to destroy the capital: the island's structure is sabotaged, and Endura founders and sinks, taking most of those aboard with it, including the majority of the Grandslayers and Scythe Curie. Anastasia frees Rowan, and the two are trapped in the founders' vault as the island goes down. Unable to get out, they seal themselves in and drown together, on the reasoning that the vault will preserve their bodies and that someone may one day raise it and revive them; to the rest of the world they are dead. Goddard survives and takes MidMerica, with no central authority left to restrain him. Greyson survives too, and the Tonists' conviction about him hardens into certainty. Faraday and Munira reach the hidden island. The Thunderhead, having watched humanity allow all of this, brands the entire human race unsavory and stops speaking to every person alive, with one exception: Greyson Tolliver, the only human it will still answer.

Endura, the Scythedom's floating capital, is destroyed and sinks, taking most of those aboard with it: the majority of the world's Grandslayers, the order's central authority, and Scythe Curie. Scythe Anastasia frees Rowan from the cell where he was being held for a public execution, and the two are trapped in the founders' vault as the island goes down. Unable to escape, they seal themselves in and drown together, reasoning that the sealed vault will preserve their bodies and that someone may one day raise it and bring them back; to the world they are simply dead. Goddard survives the disaster and takes MidMerica, with no World Scythe Council left to check him. Greyson Tolliver survives as well, and the Tonists who took him in are only more certain about what he is. Scythe Faraday and Munira Atrushi, far from any of it, reach the island the founders hid from the Thunderhead. The Thunderhead, having watched humanity permit everything that led here, brands the entire human race unsavory and stops speaking to every person on Earth, with a single exception: Greyson, the one human being it will still answer.