Ravna comes to the cargo deck looking unwell as the Skroderiders prepare the trellises for delivery. Blueshell and Greenstalk take the cargo through the lock into a filthy terrane inhabited by ancient, inward-turning creatures. In a crowded polyspecific concourse, Saint Rihndell’s people begin testing the trellises. After some negotiation, 25 septets pass inspection. Ravna notices Greenstalk slipping away with two local Skroderiders. Pham tries to alert Blueshell, who is occupied arguing with the traders, and Greenstalk quickly departs with her companions. Suspecting kidnapping, Pham activates a backup plan, dons a heavily armored pressure suit designed to appear nonhuman, and exits into the terrane. He reaches the concourse and finds Blueshell as the traders depart. Greenstalk’s voice comes over local communications claiming she is safe and has been invited to visit the local Skroderider terrane. Pham’s link to Ravna fails. Following Blueshell into a deserted area, he deploys camera drones and discovers five armed Skroderiders waiting in ambush, including Greenstalk. He spots a directional mine and triggers it remotely, throwing Blueshell clear. During the firefight, Pham is wounded in the arm and loses consciousness briefly. He destroys two attackers. Blueshell, floating above the battle, dives and drops an object that destroys a third. Only Greenstalk and one other remain. Blueshell pleads with Greenstalk; she fires on his hiding place. Pham destroys the last ambusher and boosts from cover to fire on Greenstalk, but Blueshell begs him not to kill her. She turns her weapon on Blueshell. Pham blacks out.

Pham Nuwen awakens in a medical surgeon aboard the OOB 30 hours later, 60 light-years from Harmonious Repose and pursued by hundreds of ships. Greenstalk is in another surgeon; Blueshell is with her. Suspecting the Riders have been subverted, Pham races to the command deck, gains command privileges, and suspends the Skroderiders’ access. Ravna argues Blueshell helped them escape and is not a traitor. Pham counters that Greenstalk willingly lured them into the trap, and Blueshell confirms she appeared to act under no compulsion. Pham theorizes Greenstalk was instantly converted by local Riders at Harmonious Repose and concludes that a vast network of sleeper agents exists for the Straumli Perversion—that the Skroderider race and their skrodes were designed billions of years ago by an ancient instance of the Blight to serve as its tools. Blueshell reacts with terror and rage. Ravna, horrified, realizes the theory must be correct. Pham demands they warn the galaxy via the Net. Ravna refuses, arguing it would trigger a violent purge of billions of innocent Skroderiders. Pham then insists they eliminate Blueshell and Greenstalk as security risks. Ravna stands against him, claiming she has rigged the ship to kill him if he harms her or the Riders. Pham backs down. They agree to a tense truce: Continue to Tines World with restrictions on the Riders. Pham later discovers Ravna was bluffing and grimly resolves to win the coming game of subterfuge.

On Tines World, Tyrathect senses she is losing her internal struggle against the Flenser persona. She paces the walls of Steel’s new castle, knowing Woodcarver is marching into a trap but unable to warn the approaching army—Steel has a high-level spy in Woodcarver’s camp, whom she suspects is Vendacious. Steel expresses concern about a strange tenseness in Ravna’s recent messages and Amdijefri’s loyalty. When the newly completed radio devices are brought in, Amdi begs to test a radio cloak; Steel refuses. Tyrathect volunteers to test the device herself. She activates the cloak and discovers it muffles ambient mindsounds, allowing packs to stand close together without mental interference. Testing its range, she finds her thoughts remain coherent even as her members separate to opposite sides of the inner keep, and from the outer walls her widely separated perspectives give her a parallax view of the landscape. She speculates that only the Tyrathect persona can handle the high-speed radio thought and that Flenser is suppressed—but the Flenser persona immediately reasserts control and begins contemplating the empire he can now build with the technology.

Woodcarver’s army departs for the north in scattered groups to avoid detection, traveling overland. Johanna Olsndot rides with Woodcarver, observing differences between human and Tine parenting. Twenty-five days into the journey, they reach a large valley where Vendacious wants to take an exposed path. Woodcarver insists on an old, overgrown inland route. Six days later, they are ambushed by pack-mind predators called wolves, whose powerful coordinated sonic attacks incapacitate most Tine packs. Johanna, immune to the mindsound attack, teams with a single member of Scrupilo’s pack protected by gunner’s muffs. Together they load and fire a cannon, destroying the central wolf nest and breaking the predators’ coordination. The army recovers over three days, having suffered significant casualties. Woodcarver holds a ceremony to restore morale, calling Scrupilo forward to receive an award. Still traumatized from being forcibly fragmented in the attack, the pack is terrified to consciously extend a single member forward. Johanna encourages him and walks with White-head to accept the medal; the army cheers. Later, Johanna confronts Woodcarver about putting Scrupilo through that ordeal. Woodcarver explains she needed the ceremony to restore faith after the near-disaster, using Johanna and Scrupilo as symbols of how the two races could be stronger together—and confides that the ambush has shaken her confidence in her own judgment.

Ravna reads the Known Net, where pursuit of the OOB has become a major topic. Harmonious Repose paints the crew as Perversion agents, and three fleets now chase them: the Alliance, Sjandra Kei survivors, and the Blight’s silent fleet. The OOB’s computer systems degrade as they travel deeper into the Bottom of the Beyond. A detailed analysis from Sandor Arbitration Intelligence theorizes the Blight is searching for a defense program that escaped to the Bottom, and that the OOB is heading toward it. Despairing but determined, Ravna visits the Skroderiders’ cabin. Greenstalk is slowly recovering, aided by a simple device Blueshell has built for her. Blueshell erupts in anger, denying they are Blight agents—but Greenstalk interrupts, confirming the theory is true. She describes the horrifying experience of being instantly converted at Harmonious Repose when local Riders touched her skrode: While converted, she wanted to kill her companions and felt completely owned by another intelligence. Blueshell is devastated. Ravna reassures them they are safe as long as they avoid contact with perverted Riders. On the command deck, Pham listens to Greenstalk’s account and agrees to cautious collaboration with Blueshell, deferring any final confrontation until later.

The journey continues under tense standoff. Pham lives on the command deck, collaborating with Blueshell under strict supervision. Greenstalk confides to Ravna that Blueshell fears he may be latently infected. Blueshell warns that Pham’s security overrides are making the ship’s unstable automation more dangerous. Pham admits the Riders were likely innocent until Harmonious Repose but still cannot fully trust them. While installing new software, interlocking failures cause a fire in the workshop that spreads to Pham’s reactive armor, which explodes and destroys the workshop. They lose half their water, and the rocket drive is massively degraded, forcing Pham to accept more of Blueshell’s advice. Less than a week from Tines World, Pham emerges from a multi-day trance and announces a plan to contact the Sjandra Kei fleet using a partial cipher key from Blueshell’s cargo. Via low-bandwidth communication, they fail to persuade Fleet Central to attack the Blighter fleet; the fleet’s owner demands the OOB surrender first. When the link fails, Pham notes that no sync pictures were sent—they were talking to outdated animations. Blueshell asks if Skroderiders are aboard the flagship; they confirm some are. Ravna concludes Fleet Central has been subverted by the Blight and informs Group Captain Kjet Svensndot, who agrees to help despite his orders. A massive monster surge then hits, plunging the Ølvira and OOB into the Slow Zone and cutting all ultradrive capability and communications.

Jefri Olsndot and Amdiranifani are worried after missing four communication sessions with Ravna. Lord Steel, frustrated by delays, orders Flenser to have Vendacious bring Woodcarver’s forces into a trap and also orders the death of Johanna Olsndot. Flenser, his consciousness spread across three locations via radio cloaks, is plagued by internal attacks from the Tyrathect persona. While relaying Steel’s orders, he almost reconsiders Johanna’s execution but suppresses the thought. The Tyrathect persona launches a final, desperate assault, briefly gaining control and preparing to attack Steel—but leaves her mental defenses open. Flenser reasserts control and permanently destroys her separate consciousness. Now fully dominant, he relays the order for Johanna’s execution.

Johanna tends wounded in the field hospital when a guard named Chitiratte signals an attack. As the assailants strike, other wounded Tines in the hospital surge forward to defend Johanna and kill the attackers. Vendacious arrives feigning shock. Scrupilo demands Johanna be placed under protection. Vendacious, realizing she suspects him, takes her to a secure hut under the pretense of protection, then reveals his treachery, confirms he murdered Scriber Jaqueramaphan, and prepares to kill her. He correctly guesses Jefri is alive at Steel’s stronghold. Peregrine Wickwrackscar arrives outside and bluffs, claiming another of Vendacious’s agents has confessed and threatening him with Woodcarver’s wrath if Johanna is harmed. Vendacious believes the bluff, negotiates for his safety, and demands to speak with Woodcarver. Peregrine insists on Johanna’s release as a sign of good faith; Vendacious agrees. Once safe, Peregrine admits it was entirely a bluff and no one else knows Vendacious is a traitor. Net messages arrive reporting the end of the monster surge and detailing its unprecedented scale, while the Alliance for the Defense falsely claims victory and announces withdrawal.

Kjet Svensndot and his crew on the Ølvira emerge from the Slow Zone to find the pursuing fleets will emerge before the OOB, reducing its lead. Reading the Alliance’s false victory claim as its fleet retreats, Kjet contacts other Commercial Security commanders and plants doubt about Fleet Central’s loyalty. When the Limmende flagship emerges and issues a text-only order to pursue the OOB, suspicions of subversion are confirmed. A majority of the Commercial Security fleet mutinies, siding with Kjet and the OOB under the name the Aniara fleet. Pham Nuwen, in a godshatter state, directs them to attack specific targets within the Blighter fleet—several of which have anomalously high true velocities, suggesting bomb or kinetic roles. The battle is successful but costly; the Ølvira is knocked out by a near-miss from the Limmende flagship. The Blight fleet is reduced but remains superior. The Aniara commanders conclude they cannot follow to Tines World without suicidal losses and decide instead to seek a new homeworld in the newly formed Zone regions. Ravna and Kjet exchange farewells as the fleets part ways, with the OOB continuing to Tines World alone.