Darrow, a prodigy Helldiver in Mars’s mines, is defined by hunger, danger, and the memory of his father’s hanging. To win scarce rations for his clan, he defies orders during a gas scare and nearly dies hand-scanning a drill, only to learn at Laureltide that the prized Laurel is rigged for a rival crew. His wife, Eo, coaxes him through rage into a forbidden biodome where they glimpse sky, and she demands he “live for more.” Caught returning, they are arrested. In a staged spectacle before the ArchGovernor, Darrow is flogged and Eo sings a banned song; her courage becomes a symbol as she is hanged.

Shattered, Darrow secretly buries Eo in the hidden garden and then submits to his own execution—only to awaken in a grave, dug up by operatives of the Sons of Ares. Led by Dancer and Harmony, they reveal the truth: Mars is already terraformed; Reds like Darrow have been lied to for generations, enslaved beneath a false frontier. They offer not solace but a mission. Darrow agrees to be “carved” into a Gold by Mickey the Carver, surviving excruciating surgeries, cognitive rewiring, and brutal training. Matteo, a Pink tutor, polishes his manners, language, and war-dance; Dancer grounds him in purpose. Darrow keeps his name—Darrow au Andromedus—and prepares to infiltrate the elite Institute.

At testing, he displays cunning and endurance. He befriends Cassius au Bellona and notices a sharp girl who later proves to be Mustang. After a near-perfect entrance score, Darrow is drafted to House Mars by the unkempt Proctor Fitchner. The Institute’s first lesson is murder: the Passage traps pairs in a room where only one may leave. Darrow kills Cassius’s gentle brother Julian to survive, a guilt that stalks him, and the survivors are thrown into a yearlong war among twelve Houses to learn conquest, law, and supply.

House Mars fractures. The brutal Titus hoards power through fear while Antonia blocks any election. Darrow leads a starving coalition of “dregs,” withholding fire to keep Titus from consolidating. After Titus captures slaves and abuses them, Darrow engineers outside pressure, lures House Minerva to attack, and—after a failed parley and Quinn’s capture—enlists Sevro, a feral misfit, to steal Mars’s standard. With Sevro’s help, Darrow raids Minerva, steals their standard, and springs an ambush at Mars’s keep, capturing numerous Minervans. Inside Mars, he confronts Titus, hears slips that reveal Titus is a carved Red consumed by vengeance, and determines Titus must die to protect the larger cause. He lets Cassius duel Titus; Cassius butchers him, reclaiming fear but staining Darrow’s claim to justice.

Darrow reforms Mars: bans rape, elevates the lowborn, and forges the Howlers under Sevro. He courts alliance, recruits House Diana, and topples Minerva with a decoy duel against the giant Pax while Howlers burst from dead horses to seize the gate. Mustang retreats and escapes; later, Antonia betrays Darrow, murdering Lea and driving Roque missing. A Pluto emissary brings blades and a bounty from the Jackal, the ArchGovernor’s son. Soon after, the Jackal’s holo exposing the Passage reaches Cassius, who lures Darrow into the snow, declares him Julian’s killer, and wins a duel—stabbing him and leaving him to bleed out.

Mustang finds and shelters Darrow in the Northwoods. As he heals, she challenges his fear-based rule and argues for decentralized, voluntary loyalty. Their philosophy reshapes his strategy. Proctor Fitchner reveals the game is rigged for the Jackal; Proctors sabotage from above. Darrow refuses to hide. He recruits Oathbreakers with Mustang by offering equality, flips Mars’s enslaved workers at a bridge ambush, frees Pax, and reasserts his legend by infiltrating Mars’s keep. To feed his army, he seizes House Ceres’s ovens in a swift daylight assault. When Tactus attempts rape, Darrow publicly flogs him and then takes lashes himself, declaring a code that binds power to responsibility and wins deeper loyalty.

Southward, Darrow hunts House Apollo. He stages weakness to lure cavalry through broken river ice and endures escalating sabotage until Proctor Apollo personally ambushes him with a Carver-bear. Sevro rescues him. Darrow removes his ring to evade surveillance, fractures his force into agile cells, raids Apollo’s holdings for a week, and baits Apollo into a parley while Sevro and Tactus slip through latrines to open the castle. In the plaza battle Darrow breaks Novas, Apollo’s Primus, and captures the standard, then hurls a pulse spear at the watching Proctors, naming Jupiter next.

Fitchner privately returns Darrow’s knifeRing, warns that the Proctors’ meddling is political, and—revealed as Sevro’s father—begs caution. Darrow knocks him out and marches through a blizzard to besiege Jupiter, forcing a surrender and isolating a timid envoy, Lucian, whom he unmasks as Pluto. He springs a trap for the Jackal in Jupiter’s halls, pinning his hand. The Jackal severs it to escape as Proctors jam the air. In the chaos, Pax is killed saving Darrow. Apollo abducts Darrow midair and threatens Mustang; Darrow kills Apollo with his knifeRing and gravBoots and rallies the Howlers to strike Olympus, the Proctors’ seat.

Darrow leads a vertical assault on Olympus, capturing multiple Proctors—Venus, Juno, Mercury, Vulcan—and dueling Jupiter on the slopes before Sevro, cloaked, cripples him. With the armory seized and Venus House armed, Olympus falls and Mustang is recovered. Fitchner then reveals Mustang’s identity: Virginia au Augustus, the Jackal’s twin. Realizing he has armed her and sent her after her brother, Darrow races to relieve House Mars, shatters a siege, rescues crucified enemies for healing, and reunites with Roque. Cassius rejects reconciliation and formally declares a blood feud.

Mustang returns with the Jackal bound and gagged, ending the contest. As dignitaries arrive, the disgraced Proctors are displayed and recruiters swarm. ArchGovernor Nero au Augustus privately confesses his hand in the rigged game and offers patronage, armies, and the Academy if Darrow joins him and holds his tongue. Choosing the path that grants leverage for the future war he intends to wage, Darrow kneels and swears as Augustus’s lancer, rising from the Institute as its champion while the larger rebellion he dreams of waits beyond.