Chapter Summaries

Erebus arrived on Devon and tricked its governor into accepting the Blade of Calamity as an official token of the Imperium of Man. The governor admired the sword, unaware that it had begun to murmur in his hands.

• Erebus left the returning convoy and traveled to Devon, where Horus's expeditionary forces had recently brought the planet into the Imperium of Man.
• Erebus met the Planetary Governor while disguised as a member of the Sons of Horus Legion.
• Erebus falsely claimed that the Imperium gave every Planetary Governor a token and handed him a box containing the Blade of Calamity.
• The Planetary Governor opened the box, mistook the sword for a fitting symbol of imperial military achievement, and praised its craftsmanship.
• The Planetary Governor heard strange murmuring from the Blade of Calamity but dismissed it and continued admiring the sword.

Horus returned to Devon Star after its governor rebelled and found the planet overrun by mutated creatures. He entered a mysterious temple and confronted the transformed governor, who attacked him with the Blade of Calamity.

• Horus received word that Devon Star had rebelled under its Planetary Governor and returned with the Sons of Horus to investigate.
• Horus found the planet covered in human-derived Xenos monsters and corrupted buildings, then ordered Abaddon to bombard its surface.
• The bombardment destroyed nearly everything on Devon Star but left a strange temple untouched, so Horus ordered a landing.
• Horus led more than ten thousand Space Marines into the temple, where a distortion separated him from his troops.
• The transformed governor told Horus that ancient beings had chosen him, then lunged at him with the Blade of Calamity.

Horus defeated the governor but was wounded by the Blade of Calamity, and the revelation of his strange internal organs made him question whether Primarchs were human. In his consciousness, the Chaos Gods showed him the Emperor’s past bargains and plans, then offered Horus their help with revenge.

• Horus fought the governor as the governor’s strength and skill grew under the blessings of the God of Growth and the God of War.
• Horus severed the governor’s weapon hand, but an arm of intestines caught the Blade of Calamity and stabbed through Horus’s armor, flooding him with Chaos power.
• The governor died, and Horus discovered unfamiliar organs inside himself before collapsing; the bystanders, including Abaddon, fled with him as space and time returned to normal.
• In his consciousness, Horus witnessed the Emperor’s bargain with the Chaos Gods, the Primarchs’ creation, and the Emperor’s plans for the Thunder Warriors and the Great Purge.
• The Chaos Gods offered Horus help with revenge in exchange for his allegiance, and Nurgle told him that Primarchs were essentially unrelated to humanity.

Horus concealed his doubts about his strange body and the Chaos Gods’ power while resolving to rely on himself. On Prospero, Magnus sent a powerful psychic message to Terra to warn the Emperor that Horus was being corrupted, despite the danger of doing so.

• Horus told Abaddon that his concern was not about his pain, while keeping the truth about his alien organs from him.
• Horus realized that the Chaos Gods had given him power without forcibly corrupting him, and he vowed not to rely too heavily on it.
• Magnus sensed that Warp Space was eroding Horus, but his attempts to warn him failed.
• A Warp Storm trapped Magnus on Prospero, while the Emperor’s order barred him from contacting the Emperor psychically.
• Magnus gathered his psychic strength and sent a spell through Warp Space toward Terra to warn the Emperor about Horus.

Magnus’s secret research, unknowingly steered by Tzeentch into Chaos Knowledge, turned his psychic communication spell into a devastating attack. It struck the Emperor’s Warp Network gateway on Terra, changing its destination and letting Warp Demons pour into the imperial palace.

• Magnus secretly continued researching psychic power after the Emperor rejected his proposal and ordered him to stop.
• Tzeentch had guided Magnus’s research for years, leading him to develop Chaos Knowledge instead of the psychic power he believed he was studying.
• Nurgle, Slaanesh, Khorne, and Tzeentch altered Magnus’s spell, greatly increasing its power and turning its information into Warp Demons.
• Magnus’s spell struck the Emperor’s Space Door on Terra, killing or injuring nearly all the Adeptus Custodes and scientists in the laboratory and altering the gateway’s destination.
• The Emperor recognized Magnus’s psychic signature and roared his name as Warp Demons surged through the gateway into the laboratory.

The Emperor activated the Warp Limiter to shrink the Space Door on Terra, trapping himself at the device until someone else could sustain it. He ordered Leman Russ to capture Magnus, while Horus considered how dangerous Russ would be if he ever turned against the Emperor.

• Eric Taranis and other powerful Warp Demons attacked the defenders as the Emperor realized they could not hold the Space Door indefinitely.
• The Emperor ordered Makado to hold off Eric Taranis and drained his psychic power and Life Force to activate the Warp Limiter.
• The Warp Limiter shrank the Space Door, but the Emperor had to remain and continuously power it or the portal would reopen.
• The Emperor ordered Leman Russ to capture Magnus and bring him to Terra to take over the Warp Limiter.
• Horus received the order and recalled that Leman Russ and the Space Wolves Legion could suppress and destroy other Primarchs, making them a threat if Horus betrayed the Emperor.

Horus resolved to rebel against the Emperor and planned to use Chaos before discarding it. After Magnus’s psychic spell damaged Terra, the Emperor ordered Leman Russ to destroy Magnus and his Legion, while Tzeentch offered Magnus a way to survive in exchange for serving him.

• Horus asked Abaddon how the Legion would be treated once the Imperium was stable, then decided to seize what he believed they deserved by rebelling.
• Horus told Leman Russ that Magnus had violated the Emperor’s orders and damaged Terra, and ordered him to eliminate Magnus and the Sons of Magnus Legion.
• Leman Russ accepted the order, recognizing that the deployment of the Adeptus Custodes and Sisters of Silence showed the Emperor’s fury.
• Magnus sensed the Emperor’s anger and realized his psychic spell had caused a disaster.
• Tzeentch revealed that he had schemed against Magnus and offered to save him if Magnus agreed to serve him, warning that Leman Russ and the Emperor’s forces were coming.

Magnus chose to accept the Emperor’s punishment and gave his sons a chance to flee, but some of his warriors prepared to resist. Meanwhile, Lorgar approached Angron to recruit him against the Imperium, only for Angron’s Butcher’s Nail to interrupt their conversation and leave him unable to remember what Lorgar had said.

• Magnus rejected Tzeentch’s demands, ordered his Legion not to resist, and shut down the defenses around their homeworld.
• Magnus activated nearby spacecraft so those who wished to leave could escape, but many of his warriors organized a counterattack against the Space Wolves Legion, the Adeptus Custodes, and the Sisters of Silence.
• Magnus confined himself and let his warriors act, knowing their resistance was futile against the forces sent to capture them.
• Lorgar sought out Angron and declared that he wanted to destroy the Imperium of Man and the Emperor, but Angron suspected he was being tricked.
• The Butcher’s Nail caused Angron to fall into agony, so Lorgar poured psychic power into him to stabilize him.
• After recovering, Angron asked Lorgar to repeat why he had come, having forgotten their conversation because part of his brain had been cut away.

Lorgar persuaded Angron to travel to Nuceria by promising to cure the Butcher’s Nails, then led him to a history book that twisted the story of his rebellion and abandoned companions. Enraged by the account, Angron went berserk and began slaughtering Nuceria’s inhabitants.

• Lorgar told Angron he could cure the Butcher’s Nails, and Angron reluctantly agreed to go with him.
• Lorgar brought Angron to Nuceria and led him to a bookstore, where he gave him a book about the planet’s history before leaving with the others.
• Angron read a passage portraying his rebellion as a disgraceful farce and claiming he had abandoned his companions.
• Angron erupted in rage, destroyed the bookstore, and attacked everything around him.
• Angron slaughtered millions in the city before charging across Nuceria and beginning a planet-wide bloodbath.

Lorgar began a ritual using Angron’s slaughter of Nuceria to make him ascend into a Daemon Prince. After the ritual restored Angron’s clarity, he pledged loyalty to Orsaga and asked him to save the World Eaters from the Simplified Butcher’s Nails.

• Lorgar dismissed Angron’s adjutant’s doubts and let Angron slaughter Nuceria for more than a week.
• Lorgar began the Ascension to Demon Ritual by sending a blood-colored crystal to brand Angron.
• Orsaga appeared in Angron’s mind and asked whether he wanted to become his lackey.
• The ritual restored Angron’s clarity, and Angron pledged loyalty to Orsaga while pleading for help for his children.
• Orsaga gave Angron knowledge of a surgery to remove the Simplified Butcher’s Nails, and Angron accepted the ritual’s power and began ascending toward becoming a Demon Prince.

Angron Tarka completed the Ascension to Demon Ritual, emerging with a powerful new form and a newfound calm. After his sons mistook him for an impostor and attacked, he proved his identity, then told Lorgar Aurelian that he still intended to repay the hatred of the past.

• Angron vanished as the Ascension to Demon Ritual began, leaving behind blood that spread into a vast lake beneath storm clouds and lightning.
• Angron emerged from the blood lake transformed, tore apart the storm with his greatsword, and discovered that his strength had increased several times over.
• Angron flew to the warship and returned to his human appearance, but his newfound calm and smile alarmed the World Eaters.
• A World Eater attacked Angron, accusing him of impersonating their lord, so Angron subdued the Legion members until they recognized him.
• Lorgar Aurelian congratulated Angron on his rebirth, and Angron replied that he still needed to repay the hatred of the past.

Angron agreed with Lorgar to prepare for rebellion against the Emperor and purge loyalists from their Legions. On Prospero, Magnus broke out of confinement after the slaughter of his people, and he and Leman Russ faced one another on the battlefield.

• Angron asked Lorgar about the rebellion, and Lorgar said Horus would lead it with the support of other traitorous Primarchs.
• Lorgar proposed purging loyalists from their Legions, and Angron agreed after insisting they first identify them carefully.
• Leman Russ led the Space Wolves, Sisters of Silence, and Adeptus Custodes in devastating the Sons of Magnus and the people of Prospero.
• Magnus heard his surviving sons awaiting death outside his confinement chamber and unleashed a psychic roar that destroyed nearby Space Wolves.
• Magnus emerged from the chamber as Leman Russ stepped forward, and the two Primarchs faced each other with reluctance.

Leman Russ and Magnus fought a brutal battle while their legions clashed around them. Russ gained the upper hand and finally snapped Magnus’s spine, though Magnus’s scream unleashed a wave of psionic force.

• Magnus hurled a vast sphere of psionic lightning at Leman Russ, who pierced it with the Spear of the Drunken God and neutralized its power.
• Leman Russ charged Magnus and used the Emperor-granted ability that suppressed much of Magnus’s strength, but Magnus evaded and countered with psionics.
• The Primarchs fought at blinding speed as the Sons of Magnus and their enemies continued battling for hours, until the Sons of Magnus numbered just over a thousand.
• Leman Russ stabbed Magnus several times and prepared to finish him, but Magnus unleashed plasma to knock the spear from Russ’s grasp and grappled him.
• Leman Russ overpowered the badly wounded Magnus and snapped his spine over his knee, while Magnus’s scream disoriented the surrounding Space Marines.

Magnus accepted Tzeentch’s terms and vanished with his surviving sons, while Horus used the incident to strengthen his rebellion and mislead the Imperium. Months later, rebel Legions launched surprise attacks on loyalists, and the Imperium’s enemies and uneasy allies began maneuvering as the revolt spread toward Terra.

• Magnus accepted Tzeentch’s terms, and Tzeentch’s power freed him from Leman Russ and sent him and the surviving Magnus’s Sons into Warp Space.
• Horus told Leman Russ that Magnus had defected to the Xenos Races, then transferred him to the Takkare Galaxy while considering how to resist Chaos.
• After screening their Legions and removing loyalists, the rebel Primarchs began their uprising by attacking loyal Space Marine Legions by surprise.
• The Word Bearers ambushed the Ultramarines, and Lorgar gravely wounded and captured Robert Guilliman with a weapon gifted by Orsaga.
• Other rebel Legions crippled three more loyalist Legions, reducing the Imperium’s available forces to less than a third as rebel forces advanced toward Terra.
• The Eldar and other Xenos Races began aiding the Imperium to avoid facing its enemies alone, while the Esoteric Sect worked to destabilize the Imperium and corrupt Space Marine Legions.

Eldrad Ulthran ordered Eldar assassins to target the Esoteric Sect while learning that Necrons were awakening in the Trazyn System. Meanwhile, Horus reached Terra after Xenos attacks delayed his advance and began a costly campaign to land Space Marines under fire.

• Eldrad Ulthran blamed the Esoteric Sect for disrupting his prophecies and ordered Eldar assassins to eliminate them.
• Eldrad Ulthran received a report that many Necrons were awakening in the Trazyn System and recognized they would need to be stopped.
• Horus endured more than a hundred assassination attempts, left part of his forces to hold off the Xenos attackers, and accelerated his advance toward Terra.
• Horus arrived at Terra, where loyalist forces and civilians stood ready to defend the planet.
• Horus's fleet found its bombardment ineffective against Terra's defenses and suffered losses from ground fire.
• Horus ordered Space Marines to descend in drop pods through enemy fire and destroy the anti-aircraft positions.

Sanguinius and Rogal Dorn defended the imperial palace as Angron arrived and urged Sanguinius to surrender. Horus then claimed Sanguinius as his opponent, while Angron chose to fight Rogal Dorn instead.

• Sanguinius ignored the voice from Warp Space and stood with Rogal Dorn as rebel drop pods descended on Terra.
• Angron arrived in a transformed form, and Rogal Dorn condemned his fall to Warp Space.
• Angron recognized Sanguinius's past kindness and offered him a chance to surrender, but Sanguinius refused.
• Horus arrived and asked Angron to leave Sanguinius to him, confirming the death Sanguinius had foreseen.
• Angron challenged Rogal Dorn, who charged into battle with him.

As the loyalists’ defenses across Terra crumbled, Makado took the Emperor’s place on the Warp Inhibitor so the Emperor could intervene. The Emperor arrived at the imperial palace just in time to save Rogal Dorn and Sanguinius from Angron and Horus.

• Horus offered Sanguinius equal power if he joined the rebels, but Sanguinius refused and the two began fighting.
• Makado volunteered to maintain the Warp Inhibitor, and the Emperor accepted, knowing the duty would cost Makado his life.
• Makado took the Emperor’s place on the Warp Inhibitor while the exhausted Emperor drank restorative potions and set out to suppress the rebellion.
• Angron and Horus prepared to kill the gravely wounded Rogal Dorn and Sanguinius, but the Emperor struck them with golden beams and sent them flying.
• The Emperor strode toward the battlefield, and the rebels recognized him and lost confidence.

The Emperor fought Angron and Horus while saving Sanguinius and Rogal Dorn, and the clash tore open Terra’s spacetime. Eric Taranis emerged through one of the rifts and joined Angron and Horus in a three-way assault on the Emperor.

• Angron hurled a metal wall at the Emperor, then emerged from behind it and attacked with his greatsword.
• The Emperor used psychic power to stabilize Sanguinius and Rogal Dorn, teleported them to safety, and countered Angron and Horus.
• The three combatants’ powers obliterated the surrounding area and left vast Spatial Rifts across Terra.
• Eric Taranis forced his way through a Spatial Rift and appeared on the battlefield.
• Angron, Horus, and Eric attacked the Emperor together as distant rebels and loyalists watched helplessly.

After the Emperor forced Angron and Eric Taranis out of the Physical Universe, he fought Horus at a disadvantage until the Chaos Gods withdrew their power from Horus and the Emperor killed him. The leaderless rebels were crushed, while Orsaga declared that the game had officially begun.

• Angron and Eric Taranis were forced back into Warp Space by the Emperor and the Physical Universe’s suppressive force.
• Horus told the wounded Emperor that he planned to replace him, and accused him of treating the Primarchs and their forces as sacrifices.
• Horus unleashed a devastating attack that plunged half of Terra into darkness and shook fleets across space.
• The Chaos Gods withdrew Horus’s power at the decisive moment, and the Emperor’s weapon pierced Horus’s body, killing him.
• The Emperor defeated the leaderless rebels, while Orsaga smiled in Crimson Heaven and said, “The game officially begins.”

The Chaos Gods’ game officially began after Horus died, leaving the weakened Imperium vulnerable to the rebel Primarchs. Decades later, the Silent King received news that the Necrons were awakening in force and the Eldar Empire had fallen, and prepared to return to the Milky Way.

• The Chaos Gods mocked Horus and treated his death as the opening move in Orsaga’s game to destroy the Imperium.
• Orsaga observed that the Emperor’s need to maintain the Warp Inhibitor left him weakened and gave the rebel Primarchs a chance to challenge him.
• Decades later, an encrypted message reached the Silent King beyond the Milky Way, reporting the Necrons’ mass awakening and the destruction of the Eldar Empire.
• The Silent King, who had spent sixty million years building power outside the galaxy, saw the news as his chance to reunite with his people and reclaim the Milky Way.