Chapter Summaries

Horus was resurrected on Gamma World, learned the truth of the Emperor’s role in the Imperium’s history, and returned to life bound by the Emperor’s power. He vowed to fight Chaos and its traitors as Gamma World dispatched him toward Wyrmwood to seize Vashtorr.

• Horus relived the Imperium’s history and regretted helping bring about its suffering.
• Trazyn attempted to steal Horus from the Ozrax Psyker Laboratory, but Gamma World’s temporal defenses trapped him and thwarted the retrieval.
• Gamma World repaired Horus, bound his soul to the Emperor, and prepared him with armor, weapons, and the Emperor’s Sword.
• Horus awakened, vowed to destroy the Chaos Gods and punish the traitors, and declared that he had returned.
• Gamma World ordered Horus to take Wyrmwood and capture or weaken Vashtorr, then sent the fleet onward.

The Emperor’s forces defeated Chaos’s attempt to seize Horus, prompting the Four Gods to consider another plan. On Cadivan, Horus returned and confronted Black Legion raiders, who realized he opposed Chaos and began killing their own allies to seek his forgiveness.

• Gamma World shut down its psychic channel after the Emperor’s Cursebound Legion drove back the daemons and thwarted Chaos’s plan to seize Horus.
• The Four Gods considered infusing someone else with their power and repeating their stabbing plan.
• Sahaal and Mita prepared to flee Cadivan as Chaos raiders attacked the planet in search of its blackstone anti-daemon technology.
• Sahaal glimpsed a figure resembling Horus wielding the Emperor’s Sword, but chose to leave without involving himself in the conflict.
• Horus appeared before Abaddon’s Black Legion raiders, and they recognized him as their father fighting against Chaos.
• A Black Legion raider killed a Chaos creature that tried to mislead them, and the raiders turned on their Chaos forces to seek Horus’s forgiveness.

Horus returned to Cadivan, slaughtered Chaos forces, and ordered the Expeditionary Force to seize the world as he began reclaiming his former Legion and the Imperium’s lost territory. As Astropaths prepared to report his return, an Inquisition officer questioned who Horus was.

• Four Black Legion Marauders turned on Chaos soldiers, while two new recruits attacked Horus and a Daemon Engine called Roarer joined the fight.
• Horus drew the Emperor’s Sword, vowed to undo the damage he had caused, and resolved to rebuild his Legion and bring his descendants back to the Imperium.
• Horus killed a Chaos Daemon and destroyed Roarer, then routed Chaos forces across the battlefield as two Black Legion recruits considered fleeing.
• Horus ordered the Expeditionary Force to take Cadivan and vowed to reclaim the Imperium’s lost domains while waging war against the Four Gods of Chaos.
• Cadivan’s Astropaths prepared to report Horus’s return to the Adeptus Astra Telepathica, and an Inquisition officer questioned the name.

An ordinary man’s memories of Horus surfaced, prompting the Inquisition to investigate as reports of Horus’s return spread through the Chaos forces. Abaddon learned the news and ordered Renster to deal with Black Legion members whose loyalty to Horus threatened his control.

• An inquisitor shot a man who identified Horus as the Imperium’s Warmaster, then ordered the news contained while he went to investigate.
• Chaos forces fled across the battlefield as Black Marauders and Dark Mechanicum weapons turned on their own allies after memories and rumors of Horus spread.
• A Black Legion member used Chaos sorcery to send word to Abaddon that Horus had returned.
• Abaddon recalled the purpose he had built for the Black Legion and grew furious that Horus’s return could undermine his leadership.
• Abaddon ordered Abbas to tell Renster to act against the Black Legion faction most loyal to him.

Abaddon sent Black Legion veterans aboard an Ark of Omen to reclaim Karst, while Vashtorr learned of the mission and decided to seize the ships and eliminate them. Meanwhile, Horus and Angron advanced on Kadiwen, and reports of Horus’s return reached the Adeptus Astra Telepathica.

• Abaddon dispatched Black Legion veterans aboard an Ark of Omen to retake Karst, intending to keep them from interfering with his plans against Horus.
• Vashtorr learned of Abaddon's decision and resolved to take control of the Arks of Omen and destroy the veterans, bringing his realm of Wyrmwood with him.
• Abaddon prepared a massive force of Daemon Engines, Heldrakes, and Daemon Titans to face Horus, whom he planned to kill and portray as a counterfeit.
• Horus advanced toward Kadiwen with Angron, the Expeditionary Force, and Black Legion followers, while an Inquisitor recognized that Horus had truly returned.
• Astropaths transmitting news from Kadiwen became overwhelmed by psychic phenomena, and the forbidden name Horus reached the upper ranks of the Adeptus Astra Telepathica.

As Seraph "Sanguinius" returned toward the Imperium with the Fourth Legion's fleet, he learned about the Blood Angels and witnessed the suffering and military collapse across Imperial worlds. The chapter left him shaken by the Imperium's condition as the fleet continued its journey home.

• Helros received the report that Horus had returned and ordered an investigation to verify it.
• Seraph asked who led the Blood Angels and learned that Chapter Master Dante was fighting on the Outer Rim while their forces endured the Black Rage.
• The account described Imperial forces stretched thin across countless fronts, including Blood Angels fighting Tyranids at Ubis World Fortress for more than a hundred days without reinforcements.
• On Martimia Forge World, Tyranid and Ork wars and a shortage of Space Marines left neighboring worlds exposed and mortals desperate enough to turn to Chaos.
• Seraph surveyed the Imperium's suffering through Gamma World's scans and was told that there was nothing they could do to help without destabilizing the Imperium further.

Seraph accepted that returning to the Imperium might delay its inevitable destruction, while Renster’s Black Legion fleet was ambushed after its ship systems failed. At Kadiwen, Horus saw Wyrmwood’s arrival and concluded that Vashtorr and Abaddon were cooperating only warily, leaving their forces divided across separate battlefields.

• Seraph accepted the others’ account of the Imperium’s fate and ordered them to descend, believing their arrival could delay its destruction.
• Renster’s Dark Mechanicum discovered that the Fuhun’s propulsion engines had been sabotaged, and rioting machine spirits sealed the compartment before they could warn the others.
• Renster realized the Black Legion fleet had been trapped as enemy warships appeared and its shields and weapons failed.
• Renster ordered his forces to hide in the inner compartments and let the enemy bombard the Fuhun, hoping to force them into boarding combat.
• The Expeditionary Force nearly cleared Kadiwen of Chaos forces while the space battle continued, and Horus learned that Wyrmwood had appeared elsewhere.
• Horus concluded that Abaddon and Vashtorr distrusted each other and that their forces’ separation eased the pressure on Gamma World.

Horus faced Abaddon and the Black Legion on a devastated planet, while Abaddon struggled to accept that the father he had fought for was alive and standing against him. Abaddon charged Horus, who met him without retreating.

• Horus learned that Abaddon and the Black Legion had arrived as part of the effort to draw Vashtorr out, and their assault devastated the planet.
• Abaddon teleported from the Vengeful Spirit to the battlefield and found three Black Marauders who had sided with Horus; he used psychic power to disable them.
• Abaddon challenged Horus to appear, and Horus emerged from the smoke protected by warship-grade force-field shields.
• Abaddon accused Horus of leading the Legion into ruin and declared that he had to kill him so the Black Legion's ten thousand years of war would retain meaning.
• Horus considered whether to regard Abaddon and the Black Legion as erring sons or as tools, then stood his ground as Abaddon charged.

Horus fought Abaddon, who rejected his attempt to turn back and sought to kill him, while Horus held back rather than finish him. On Kadiwen, Modasfern’s Slaanesh legion mistook the Chaos forces for invaders and rallied to defend the Imperium in the Emperor’s name.

• Abaddon attacked Horus and accused him of betraying the Sons of Horus, rejecting his offer to lead them back.
• Horus warned that Chaos was driving Abaddon toward ruin, but Abaddon persisted in his vengeance and the two clashed across the battlefield.
• Horus weakened his strike after hearing Abaddon’s accusations, but countered Abaddon’s attempt to stab him and survived through his armor and defenses.
• Black Reavers and other warbands joined the fighting on Kadiwen, while their sorcerers’ attacks were nullified by Horus’s Untouchable trait.
• Modasfern’s Emperor’s Children arrived, mistook the Chaos forces for an invasion of the Imperium, and prepared to fight them.
• Modasfern used blue ice to rouse his warriors, and they declared their loyalty to the Emperor.

Horus used the battle on Cadivan to lure Chaos factions while Gamma World prepared to test weapons that could reshape their minds. The true target was Vashtorr and the Webway Key on Wyrmwood, and Vashtorr revealed that Horus had returned as he attacked the Black Legion aboard the Arks of Omen.

• Chaos forces and Slaanesh Legionnaires fought on Cadivan, where Horus had gathered them as bait for Gamma World's Colossus experiment.
• Horus left the battlefield and directed the plan to attack Vashtorr on Wyrmwood and seize the Webway Key.
• Vashtorr, empowered by Wyrmwood, attacked the Arks of Omen, where Black Legion soldiers faced a massacre.
• Vashtorr told the Black Legion that Abaddon had tacitly approved the attack because they were an unstable factor.
• Vashtorr revealed that Horus had returned.

Renster and the Black Marauders rejected Vashtorr’s claim that Horus had returned, but Vashtorr attacked them and began turning their bodies into weapons. A Black Legion psyker broke through his psychic blockade to warn Abaddon that Vashtorr was a threat.

• Renster dismissed Vashtorr’s attempt to turn the Black Marauders against Abaddon and fired at him, but Vashtorr caught the bullet and transformed it.
• Vashtorr declared that the truth would abandon the Black Marauders and moved to seize their bodies for his own forces.
• Vashtorr used psychic power and the warship’s machinery to trap the Black Marauders and merge them with metal, flesh, and the ship’s furnaces.
• Renster led a fighting retreat and discovered that Vashtorr had imprisoned veteran Black Marauders in power cores, where they faced transformation into weapons like Heldrakes.
• A Black Legion psyker detonated his soul and body to break through Vashtorr’s blockade and warn Abaddon about him.

Vashtorr tried to defend Wyrmwood from Gamma Fleet, but the Blackstone Pylons suppressed Chaos sorcery and Gamma World’s manipulation of physical laws weakened him. He realized the attack targeted him as well as his planet and feared Gamma World would seize his Webway Key fragment.

• A psyker sent Abaddon a faint warning before Vashtorr noticed Gamma World’s fleet arriving in an eight-pointed formation with eight Blackstone Pylons.
• The Pylons stabilized the boundary between the Warp and reality, disrupting Chaos sorcery, and Vashtorr vanished while a powerful figure advanced through the Chaos forces.
• Gamma Fleet trapped Vashtorr’s fleet and bombarded Wyrmwood, forcing its defenders to rely on layers of force-field shields against relentless attacks.
• On Katest, altered physical laws made mathematicians’ calculations contradict reality, weakening Vashtorr’s body, which depended on physical conditions.
• Vashtorr realized Gamma World had come for him as well as Wyrmwood and resolved that they must not take his fragment of the Webway Key.

Horus appeared to the Black Reavers, while the Horus's Wolves learned of his return and prepared to seek prophecies about the future. On Sable Star, Lion El'Jonson confronted Seraphax, who revealed his plan to kill the Emperor and unleash the Dark King against Chaos.

• Horus appeared before Renster and the Black Reavers, who recognized their lord.
• Cain and Carl sensed Horus's return, discovered his body had vanished, and ordered Chaos sorcerers to divine the future.
• Lion El'Jonson led the Angels of Absolution to Sable Star to confront Seraphax, destroying the skull-built ritual before landing.
• Lion El'Jonson transported his sons into the misty forest and charged into the palace alone as the Angels of Absolution followed.
• Seraphax told Lion El'Jonson that he planned to take his body, kill the Emperor, and bring forth the Dark King to destroy the Chaos Gods.

Lion El'Jonson resisted Seraphax's attempt to possess him, then freed himself and defeated the sorcerer. After ending Belo's suffering, Lion resolved to bring his fallen sons home, while an awakened Primarch on Ultramar World wondered about the words “40K, Horus, the Great Crusade.”

• Seraphax used a Tzeentchian mirror to prey on Lion's despair, but Lion remembered that his sons were not tools and rejected him.
• Belo attacked Seraphax as the Angels of Absolution entered, and a bolter shot destroyed the mirror.
• Bevidan freed Lion, who killed the sorcerer controlling his chains and struck down Seraphax, but hesitated to kill him.
• Belo cut open Seraphax's skull and severed his wings, then asked Lion to end his life because his injuries could not be saved.
• Lion told Belo that he had never betrayed the Imperium or The Emperor, then killed him and ordered Kadalan to burn the area.
• Lion resolved to bring more fallen sons home, while an awakened Primarch on Ultramar World questioned the connection between “40K, Horus, the Great Crusade.”

Guilliman reviewed the Imperium’s records and learned that the Great Rift and entrenched factions were obstructing Malcador’s reforms and the construction of a Gravity Slingshot. Malcador then heard that Horus had been found on Cadivan, while Chaos agents continued plotting against the Emperor.

• Guilliman demanded the Imperium’s recent records and learned about its dire state and the Great Rift.
• Guilliman worried about Horus’s return and whether the Emperor had ever regarded the Primarchs as sons.
• Malcador’s Gravity Slingshot project stalled amid resistance from the Adeptus Mechanicus, the Administratum, and the Navigator Houses.
• Malcador received word that a riot had broken out at a factory producing Gravity Slingshot components, delaying construction again.
• Malcador learned that Horus had been discovered on Cadivan and said the Emperor had brought him back.
• Malcador recalled that Chaos agents had infiltrated the Imperium and were trying to kill and resurrect the Emperor.

Malcador saw the drug-addled Emperor's Children rampage through Slaanesh's palace to rescue Fulgrim, while Slaanesh contemplated the Crone Sword and his possible end. In Gamma World, a powerful device enforced a reality barrier as its forces launched the Angel of Comfort Plan against the fleets fighting over Cadivan.

• Malcador saw the Emperor's Children ask for help rescuing Fulgrim, while drug-addled Necrons and daemons also shouted loyalty to the Imperium.
• The Emperor's Children seized their Chainswords and slaughtered those around them as they tried to escort Fulgrim out of Slaanesh's palace.
• Slaanesh considered the Crone Sword, fearing both Ynnead's arrival and the loneliness that would follow absorbing all Aeldari souls.
• Chaos forces found Gamma World's reality barrier strengthened, psychic powers suppressed, and a vast device operating alongside its Colossus weapons.
• Gamma World activated the Angel of Comfort Plan and sent a massive fleet to Cadivan, destroying some Chaos warships and ordering the rest driven away.

Gamma World tested a weapon that transformed Kadiwen World’s ecosystem and sealed the planet, but the experiment failed to erase consciousness without changing species. On Wyrmwood, Horus rallied the Black Reavers to fight Chaos as the Warmaster’s loyal followers.

• Gamma World’s weapon altered the life on Kadiwen World into creatures capable only of happiness, while the Angel of Comfort sealed the planet from outside interference and travel to the stars.
• Gamma World recorded that its experiment failed to achieve its goal, though it could still threaten Chaos if its power transformed enough planets.
• Gamma World’s fleets besieged Wyrmwood for nearly half a month as Vashtorr and the Dark Mechanicum struggled to keep the planet’s defenses operating.
• Horus and the Sons of Horus led a decapitation strike that destroyed a Warlord-class Titan, while the Black Legion raiders discovered Horus had returned.
• The Black Reavers pledged loyalty to Horus, recognized that Abaddon and Chaos had deceived them, and vowed to fight Chaos in the Warmaster’s name.

The Black Legion and Gamma World’s forces attacked Vashtorr’s Wyrmwood, destroying its core engines and weakening its power to resurrect its defenders. As the battlefield collapsed, Vashtorr ordered his followers to remove the Webway Key fragment, while Gamma World detected that he was leaving.

• Rens urged the Black Legion to destroy Wyrmwood’s core engines before its defenders could keep regenerating.
• Viper Squad destroyed an engine device, allowing Gamma World’s Titan-class warship to strike the exposed site with its annihilation cannon.
• Gamma World’s fleet overcame Vashtorr’s attempts to corrupt its systems and continued its assault on Wyrmwood.
• The Black Reavers charged the Slaughterfiends as Vashtorr’s base collapsed under relentless bombardment.
• A Dark Mechanicum sage urged Vashtorr to escape, but Vashtorr sensed that someone was preventing him from leaving.
• Vashtorr ordered his followers to take the Webway Key fragment away, and Gamma World detected that he was leaving.

As the Warp shuddered with an unknown disturbance, Vashtorr abandoned his forces and fled with the Webway Key fragments while Horus pursued him. Vashtorr vanished from the temple, and Gamma World’s forces continued stripping away Wyrmwood’s defenses as they waited for the keys to be secured.

• A sudden upheaval in the Warp disrupted Vashtorr’s sorcery and made Horus and other Warp-touched warriors sense a powerful disturbance.
• Vashtorr sacrificed the Dark Mechanicum forces holding off Horus and activated two Warmaster-class Titans to cover his escape.
• Vashtorr took the Webway Key fragments and tried to escape through a passage beneath his temple before the planet’s encroaching stasis field trapped him.
• Horus blasted into the temple, found Vashtorr gone, and pursued him while the Titans and daemons fought across the battlefield.
• Gamma World steadily stripped away Wyrmwood’s engine shields and considered intervening because Horus had not recovered the Webway Key fragments.

The Four Gods of Chaos learned Gamma World was close to gaining a Webway Key function that could let it search and strip the Warp, so they secretly sent daemons into the material universe to stop it. As the conflict moved toward Wyrmwood, news of Sanguinius and Horus returning spread across the Imperium and stirred panic on Terra.

• The Four Gods ordered Rons, Szarekh, and Frises to lead troops into battle as they moved to stop Gamma World's attempt to complete its Webway Key and search the Warp.
• The Four Gods secretly entered the fray by creating material bodies for daemons and sending them through Warp rifts into the battlefield.
• Tzeentch claimed that everything was proceeding according to plan while the other gods suspected he was pursuing a scheme they did not understand.
• Rumors of Sanguinius's return spread through the Imperium, followed by news that Horus had returned as well.
• Hidden residents beneath Terra prayed for Horus to destroy the Imperium, while the news of his return caused panic and fury in Imperial politics.