Armor World recap

A moon-sized Skay vessel attacks Earth, converts Hamilton's population into machine-biotic troops, and retreats to 51 Pegasi. Legion Varus follows, discovers the same conversion process among the Pegs, and sees Sateekas's fleet destroyed. Armel murders Galina Turov during a failed mutiny and identifies a Mogwa-specific bio-terminator before McGill kills him. When the Skay captures Leggett, McGill learns that Armor World is itself a single machine intelligence and trades it the poison and its formula for the ship, the legion, and Earth's safety. Back on Earth, a revived Sateekas prosecutes the human leadership over his killing and the cover-up. McGill casts Armel as a Skay agent, and Sateekas ends the case in exchange for his own sample. Galina is acquitted but does not regain the title of Imperator, while McGill returns to Waycross and reconciles with her.

Previously: James McGill is a repeatedly revived Legion Varus officer whose service has entangled Earth with powerful galactic interests. Galina Turov commands Legion Varus and remains both his superior and intermittent partner. McGill's dealings with Grand Admiral Sateekas on Mogwa Prime continue to shape Earth's standing with the Mogwa.

Earth's first boarding force enters the sphere through its immense open door and falls toward the inner hull. Communications fail, and the soldiers learn that the sealed shell cannot be crossed safely by teleport. Biomechanical flying creatures and larger quadrupeds pursue the survivors, apparently trying to capture rather than kill them. McGill sends Sargon toward the door mechanism with an antimatter charge while the others draw the defenders away. The explosion jams the opening and throws McGill into space, where he dies after transmitting what he can. McGill is revived from the data that reached Earth. The damaged sphere retreats rather than risk another attack, but it has already launched ninety-one assault shuttles and left a large invasion force behind. Central's heaviest weapons have failed to destroy the vessel, and much of Earth's advanced bomb supply has been spent. With the mothership still intact and the purpose of its ground force unknown, Legion Varus prepares for the next phase of the planetary defense.

Legion Varus and Legion Solstice deploy outside the alien dome around Hamilton while the nearby civilian population limits heavy bombardment. Ghost scouts enter first, and the apparently human figures advancing from the field prove to be converted residents. The machine-biotic attackers resist ordinary weapons, detect stealth troops, and kill Della, Barton, Natasha, and many others as McGill presses toward the town center. The depleted force burns a living production structure and reaches the generator powering the conversion operation and the dome. The device resembles technology McGill encountered on Dark World. Harris and Cooper die forcing a metal strut into its circuit, but their action shuts it down. The humanoid attackers stop, communications return, and the dome collapses. The surviving troops emerge after the enemy withdraws, only for an apparent aircraft strike to destroy Hamilton with a nuclear weapon. McGill and everyone still in the town are killed. The local installation has been disabled, but the retreating sphere remains intact and the identity of the force behind it is still unknown.

The expedition follows the sphere toward the Pegasus region rather than attempting to overtake it. Command hopes to attack after it leaves warp and to exploit the damaged entrance, since the escort cannot breach the hull directly. Armel joins as the tribune of an allied near-human legion. During the voyage, Varus officers take part in a lethal training contest whose rules favor the senior ranks. McGill persuades the lower ranks to combine their forces. Galina's armored vehicle is destroyed, Harris kills Graves, and McGill's group kills Winslade. The lower ranks win, and the dead officers enter revival. McGill and Barton begin a relationship despite their command connection. As the expedition nears 51 Pegasi, Drusus explains that the native Pegs are technologically advanced and known for artificial intelligence. The system has gone silent while the damaged sphere heads toward it. Command considers the possibility that a machine intelligence has displaced the Pegs and used their world to build strength in secret.

At 51 Pegasi, civilian craft rise to repair the sphere, suggesting that the invader controls or has absorbed the local population. Genetic evidence confirms Peg material in the hybrids that attacked Earth. Varus becomes a jump-troop force and teleports reconnaissance teams to the planet, but the sphere's damaged breach closes before they can use it. The operation expands into a full ground invasion outside Peg City. Converted Pegs attack in armored animal and walker forms. McGill advances his heavy troops to support the front line, but immense living tanks overrun the defenses with smaller beam units in support. McGill and Harris are killed, and only about half of Varus is extracted. Armel's near-human legion is almost annihilated. The tanks resist conventional heavy fire and move too quickly for reliable orbital strikes, while the domed city continues producing machine-biotic forces. Human replacements are inbound, but the revival system cannot restore the losses quickly enough, and the intelligence controlling the enemy remains hidden.

Command sends lightly armed detachments near Peg City to draw the living tanks into a bombing zone. McGill combines his survivors with Centurion Jenny Mills's force and helps disable a pursuing tank, but the strike falls elsewhere. The group shelters inside the damaged machine while radiation spreads and uncertainty about their deaths prevents safe revival. Grand Admiral Sateekas arrives with twelve Mogwa ships and insists on attacking the sphere without human support. McGill warns him about its defenses, while Galina argues that the fleet is too small. Sateekas proceeds as an imperial sacrifice after transmitting records of the encounter. The sphere adapts to the Mogwa attack, survives massive antimatter strikes, and destroys the fleet with implanted T-bombs. It also destroys the transport carrying Drusus and Legion Solstice. With Sateekas's flagship gone and the expedition badly irradiated, Galina assumes command of Leggett and orders the ship to escape into warp.

Aboard the fleeing Leggett, Armel reveals that he arranged Sateekas's revival and uses McGill to draw Galina into a trap. He kills both of them, but McGill revives under his control and kills him. The investigation confirms that Armel murdered Galina during an attempted mutiny. Before his final death, Armel identifies the invaders as the Skay, a machine-biotic galactic species, and exposes a poison designed to target the concentrated Mogwa population. Sateekas revives in a young body, and Captain Akuma begins investigating the poison claim. Drusus is also restored. Fearing that the Mogwa will report Earth's forbidden knowledge, Drusus and Graves abort Sateekas's next regrowth and secretly destroy the module holding his remaining party. The discarded module exposes Leggett's path. The Skay sphere catches the ship in warp, forces it back into normal space, and begins pulling it through the open entrance. Drusus chooses not to fight or surrender immediately, hoping the Skay may find humanity useful enough to spare.

Leggett cannot form a warp bubble inside the Skay field. Drusus deploys the legion as a diversion while McGill leads a hand-picked scouting squad across the vessel's vast interior. Their drop pod crashes into a hive-like settlement, but Leeson restores order and Cooper scouts ahead. The squad discovers an inhabited internal ecosystem and marches toward a huge organic tower while the main force prepares for another assault. Seven living tanks intercept the scouts. The soldiers blind several turrets, but Carlos and others are killed before the tanks demand a ceasefire. They identify themselves as networked children of a Skay intelligence and reject McGill's offer of human service. McGill instead promises a secret valuable enough to justify returning him to Leggett. During the journey, he realizes the entire planet-sized vessel is one artificial living intelligence, with its entrance functioning as a mouth and its mobile bodies sharing awareness. He contacts Graves and negotiates a guarded meeting between the Skay tanks and the trapped human ship.

McGill explains that Armor World is a single Skay intelligence that converts living populations into machine-biotic servants. He proposes trading the Mogwa bio-terminator for Legion Varus, Leggett, and Earth's safety. The Skay already possesses a formula purchased elsewhere, but McGill offers a working dose that can prove the weapon's effectiveness. Drusus authorizes Graves to provide both the poison and its formula. Kivi is killed while trying to escape the Skay tanks. The Skay accepts the cargo and opens Armor World's exit. Leggett escapes and enters warp for Earth. McGill's bargain saves the surviving humans without defeating their captor, and it places a Mogwa-specific weapon in the hands of a galactic rival. Drusus and Graves expect the Mogwa and Skay to contest the region despite its limited strategic value, leaving Earth vulnerable to the consequences of their struggle.

During the voyage home, Jenny Mills ends her involvement with McGill after learning about Barton, and Barton ends her own relationship with him because it is damaging troop morale. Galina is revived and confronts McGill over his decisions while she was dead. They later reconcile, and she prepares to defend herself against a court of inquiry by using McGill's theory that the Skay once controlled the province. Leggett reaches an Earth whose Central City has been heavily damaged. Drusus arrests Galina for suspected treason, but a revived Sateekas interrupts with a tribunal against the human leadership. Video evidence shows the deaths of his party and McGill's killing of Armel. McGill testifies that Armel served the Skay and portrays the bio-terminator as a Skay weapon aimed at the Mogwa. Sateekas accepts this explanation, treats Armel's death as proof of McGill's loyalty, and closes the case after requiring Earth to provide a sample. Galina is acquitted in later proceedings and remains a tribune, though she does not regain the Imperator title. Etta remains content at Central. McGill returns to Waycross, where he and Galina resume their relationship. The Skay threat, Mogwa relations, and the spread of the bio-terminator remain open.

Leggett escapes Armor World after McGill gives the Skay a working dose of the Mogwa bio-terminator and its formula. The bargain saves Legion Varus and Earth, but equips a powerful enemy of the Mogwa and leaves humanity exposed if the two galactic powers contest Province 921. Carlos and Kivi are among those killed during the Armor World mission. Galina is revived after Armel's mutiny, while Armel remains dead. At Earth, Sateekas has also been revived and convenes a tribunal over his assassination, the deaths of his retinue, and the human cover-up. McGill claims Armel served the Skay and reframes the poison as part of their campaign against the Mogwa. Sateekas accepts the defense, treats McGill's killing of Armel as evidence of loyalty, and closes the immediate case after demanding a sample. Galina survives later investigations, keeps her rank, and is acquitted, but she is not restored as Imperator. Etta remains at Central, Barton and Mills have ended their relationships with McGill, and McGill returns to Waycross before reconciling with Galina. The Skay threat, Mogwa relations, and the spread of the bio-terminator remain unresolved.