The Black Prism recap

In the Seven Satrapies, drafters turn light into luxin, a physical substance, and pay for it with their lives; the Prism alone can draft every colour, and the Chromeria governs magic in his name. Sixteen years after Gavin Guile won a civil war against his brother Dazen, a fifteen-year-old boy named Kip watches his Tyrean town destroyed by a would-be king, receives a jewelled dagger and the claim that Gavin is his father from his dying mother, and is swept up by the Prism himself. At the Chromeria Kip meets a family that regards him as a liability, while Gavin conceals two things: that his colours are failing one by one, and that he keeps a prisoner in a cell beneath the tower. When the rebellion marches, Gavin raises a luxin wall around the city of Garriston in a week and still loses it. Kip kills the rebel king with the dagger, which drinks the man's magic; Liv Danavis defects to the rebels' new leader, the Color Prince; and the reader learns that the Prism is actually Dazen, wearing his brother's name, and that the prisoner below is the real Gavin Guile.

In the Seven Satrapies, magic is drafting: a drafter converts light of one colour into luxin, a physical substance with its own properties, and pays for it with their body and eventually their life. One person in each generation, the Prism, can split light into every colour, and the Chromeria on the Jasper Isles trains and governs drafters under him and under an administrator called the White. Kip, a heavy and much-mocked fifteen-year-old, lives in the Tyrean town of Rekton with a mother lost to the drug haze. Tyrea is the losing side of the False Prism's War, fought sixteen years earlier between Gavin Guile and his younger brother Dazen and ended at Sundered Rock a short walk from the town. Kip scavenges that battlefield for scraps of old luxin. Word arrives that a man calling himself King Garadul, son of Tyrea's deposed satrap, is raising an army and marching on the towns that submitted to the Chromeria. Far away on the Jaspers, Gavin Guile tests his colours each morning, as Prisms do, and finds that the count he has been keeping in private is running out faster than anyone knows.

Garadul's army reaches Rekton and burns it, killing most of the town. Kip survives. He finds his mother dying, and she presses on him a jewelled dagger she has kept hidden for years, tells him that Gavin Guile is his father, and demands that he take revenge for her. Kip is left with a knife he does not understand, a claim he cannot prove, and no home. On the Jaspers, Gavin learns that he has a son in Tyrea. He also keeps a secret that would end him: below the Chromeria, in a cell of blue luxin, sits a prisoner whom Gavin alone visits and feeds, and who has spent sixteen years planning to get out. Karris White Oak, a Blackguard who was betrothed to Gavin before the war and has never forgiven what the war cost her family, is drawn back into his orbit as he prepares to leave the Chromeria on business he will not explain to the Spectrum.

Gavin reaches the ruins of Rekton, finds Kip, and claims him as his son in front of witnesses. They are hunted by Garadul's men and by a colour wight, a drafter who has passed the limit a body can bear and remade himself in luxin; Gavin destroys it. He carries Kip away on a craft of his own invention that skims across open water faster than any ship. Kip learns that Rekton's dyer, Master Danavis, was no provincial craftsman but Gavin's general in the war, hidden in a backwater ever since, and that he has been quietly watching over Kip for years. Kip says nothing about the dagger and keeps it out of sight. Gavin, alone, confirms what he has been dreading: one of his seven colours has gone and will not come back, which by his own arithmetic gives him about five years before the rest follow.

Gavin brings Kip to the Chromeria on Little Jasper and installs him as an acknowledged Guile bastard, which pleases nobody. The Spectrum, the council of Colors that governs alongside the White, treats a Tyrean rebellion as a provincial nuisance and is far more interested in what the Prism is doing without their permission. Kip is summoned to the sealed, lightless room of his grandfather Andross Guile, who sits as Red on the Spectrum, cannot bear light after a lifetime of drafting, and conducts the family's business and the Chromeria's politics from the dark. Andross makes Kip play the card game Nine Kings and makes plain what the boy is worth to him. Kip's grandmother Felia Guile is warmer and no less calculating. Aliviana Danavis, the dyer's daughter and a yellow drafter in her final years of study, is set to look after Kip, and the two of them recognise each other from childhood.

Kip is tested and turns out to be capable of drafting more than one colour, which makes him valuable and also a problem, and he begins the miserable business of learning to draft alongside students years younger and far better prepared. Andross Guile keeps summoning him to the dark room and the card table, and every game costs Kip something. Gavin argues with the Spectrum over Tyrea and is refused the force he asks for. Liv is pulled between her loyalty to Kip, her family debts, and the patrons who own those debts. Karris is sent south as the Chromeria's envoy to the man calling himself King Garadul, a mission designed to look like diplomacy and to gather intelligence. Gavin, unable to move the Spectrum, resolves to go to Tyrea himself and to defend Garriston, the one real city left in the satrapy, with whatever he can raise.

Karris's embassy fails; Garadul takes her prisoner rather than treating with the Chromeria, and his army moves on Garriston. Gavin sails south with Kip, Ironfist and a small force, defying the Spectrum's caution, and Liv is sent to Tyrea as well on an errand of her own patrons' devising. Garriston is a broken city, still garrisoned and still resented as the place where the war was settled, with a governor who has no intention of fighting and walls that will not stand. Gavin surveys it and decides that the only way to hold it is to build something no drafter has ever built. Kip, in the middle of all this, is being trained on the run, and continues to keep the jewelled dagger secret from everyone.

Gavin raises the Brightwater Wall around Garriston out of luxin, working the whole circuit of the city in a matter of days: a feat that has no precedent and that costs him more than he admits. The city fills with refugees from the countryside and with a scratch garrison of soldiers, sailors and untrained drafters. Kip is put to work and starts to find, painfully, that he is good for something. Liv arrives in Tyrea and is confronted with the other side of the story she has been raised on: what the Chromeria did to her satrapy after the war, and what it does to its own drafters at the end of their span. Karris, still a prisoner in Garadul's camp, learns that the rebellion is no longer really Garadul's, and that something older and stranger is directing it.

The rebel army arrives before Garriston with its own drafters and a core of colour wights who have already abandoned the limits the Chromeria sets. Gavin's defence rests on the wall, on a handful of trained fighters, and on himself, and he is quietly running out of colours to spend. Liv, travelling with the rebellion, is offered a place in it and a version of the future in which drafters are not executed once their power fails, the practice the Chromeria calls the Freeing. Karris tries to escape her captivity. Kip is armed, frightened and repeatedly told to stay out of the way. Below the Chromeria, thousands of miles from any of this, the prisoner finishes the work of sixteen years and gets his hands on the seam of his cell.

The battle for Garriston is fought over the wall and then through the streets. Gavin spends himself holding the line, and the wall he built is not enough against wights and cannon together. Kip, cut off in the fighting, comes face to face with Rask Garadul and kills him with his mother's jewelled dagger; the knife does something no weapon should do, drinking the dying man's magic into one of the seven stones set in its hilt. Karris is found and freed. The city is lost regardless, and Gavin turns from defending Garriston to evacuating it, putting the population aboard every hull in the harbour while the rebellion takes the walls.

Command of the rebellion passes to the Color Prince, a man burned nearly to ruin whose skin is cracked through with every colour of luxin, and whose ambition is not Tyrea but the destruction of the Chromeria itself. Liv Danavis chooses his side, openly and by her own reasoning. Gavin gets the refugees out to sea and leaves Corvan Danavis, his general from the war, in command of them; Karris survives and now knows Kip is a Guile; Kip keeps a dagger that has begun to fill with stolen colour. Beneath the Chromeria the prisoner breaks out of the blue cell at last and finds only another cell waiting beyond it, and in the same hour Gavin loses blue permanently. And the reader is finally told what the book has been withholding: the man the world calls Gavin Guile is Dazen. He won the war, took his brother's name, face and office, and has kept the real Gavin alive in a private prison for sixteen years. The Prism is an impostor, his failing colours are the price of it, and the boy he has just claimed as a son is the son of a dead man's name.

Garriston cannot be held. Gavin gets the city's people out by sea and leaves Corvan Danavis, his old general, in charge of the refugees, while the rebellion takes the ruined city. Rask Garadul is dead, killed by Kip with the jewelled dagger his mother left him, and one of the dagger's seven stones has filled with stolen colour, which nobody can yet explain. Command of the rebellion passes to the Color Prince, who intends to break the Chromeria outright. Aliviana Danavis, disgusted by how the Chromeria treats Tyrea and by the Freeing, the ritual killing of drafters who reach the end of their power, goes over to him willingly. Karris is recovered alive and knows now that Kip is a Guile. Beneath the Chromeria, the prisoner breaks out of his blue cell and finds only another cell beyond it, and at the same time Gavin loses blue for good. The last thing the book gives the reader is the truth behind all of it: the man the world calls Gavin Guile is Dazen. He won the war, took his dead-seeming brother's name, face and office, and has kept the real Gavin alive in a private prison ever since. Kip is the son of a man who does not exist, and Gavin's five great purposes and shrinking span of colours are the debts of a sixteen-year-old lie.