Chapter Summaries

Lox awakened from ten thousand years of stasis as the executor of the Red Alert project, intended to preserve humanity’s last hope. On Isstvan V, Nykona Sharrowkyn and Sabik Wayland’s Shattered Legion ambush killed a Death Guard patrol, but the survivors remained trapped and faced an approaching extermination force.

• Lox awakened after 3,658,765 Earth days and recalled how the chief of the Alliance Science Division had chosen him to preserve humanity’s knowledge through the Red Alert project.
• On Isstvan V, seven Death Guard searched the poisoned battlefield for surviving loyalists and tracked a wounded enemy by his blood.
• Sabik Wayland’s explosives collapsed the ground beneath the Death Guard, and Nykona Sharrowkyn emerged from the tunnels to kill the trapped traitors.
• Sharrowkyn signaled the all-clear, and Iron Hands survivors recovered weapons, armor, and enemy brain tissue from the dead.
• Wayland and Sharrowkyn learned that the Death Guard’s footsteps were drawing closer and agreed they had to escape alive.

As Iron Warriors bombard the loyalists on Isstvan V, Nykona and Wayland’s force encounters the ancient ship Red Alert and its awakened commander, Lox. After learning about Horus’s rebellion, Lox agrees to help the Astartes return to Terra and see the Emperor.

• Wayland recognized the escalating bombardment as an enemy trap and ordered the loyalists to retreat deeper through the tunnels.
• Lox awakened aboard Red Alert and piloted the ship through Isstvan V’s mantle, where it blocked the Astartes’ escape route.
• Nykona and Wayland’s warriors entered Red Alert after its hatch opened, and Lox confronted them inside.
• Lox disabled Wayland’s power armor when Wayland demanded answers, then listened as Nykona explained the betrayal on Isstvan V and Horus’s rebellion.
• Lox released Wayland, offered the loyalists supplies and rest, and agreed to take them to Terra.

Lox and the Iron Hands discovered that the Red Alert could print superior power armor and supplies, then faced an Iron Warriors fleet above Isstvan V. The Red Alert smashed through the enemy formation, destroying most of the fleet and leaving Wayland and the other Iron Hands awed by its power.

• Lox printed new power armor, food, and water, and the Iron Hands replaced their battered equipment and ate.
• Wayland recognized the Red Alert's technology as likely originating from the Dark Age of Technology, while Lox criticized the Astartes and their outdated customs.
• The Red Alert escaped Isstvan V's atmosphere as Iron Warriors warships launched missiles and surrounded it in orbit.
• Lox ordered the Red Alert to ram through the enemy fleet, and its shields absorbed a lance strike without slowing.
• The Red Alert destroyed a strike cruiser and ruptured an eleven-kilometer battleship, crushing more than half the Iron Warriors fleet.
• Wayland and the Iron Hands praised the Red Alert's Machine Spirit after witnessing its overwhelming victory.

The Red Alert entered the increasingly perilous Warp, where Lox learned that the Shattered Legions needed a Navigator and reacted with alarm to his AI, Pika. As the ship continued toward Terra, Lox shared images of ancient Earth with Nykona Sharrowkyn, who had never seen humanity’s homeworld.

• The Red Alert jumped into the Warp, and Lox increased the Gellar Field after sensing whispers and visions in the turbulent Empyrean.
• Wayland thanked Lox for rescuing the warriors and asked how the ship could reach Terra without a Navigator.
• Lox explained that his era had no Navigators and revealed Pika, whose appearance prompted the Astartes to identify it as an Abominable Intelligence.
• Lox learned about humanity’s technological decline and continued the journey with the Shattered Legions toward Terra.
• Nykona asked Lox what Terra had been like, and Lox projected footage of ancient Earth for him.
• Nykona watched the images of Earth and shed a tear.

Lox noticed that the holographic image of Terra showed an impossible number of continents, then discovered that an unknown Warp-born force had altered the flagship Prometheus’s cogitator and nearly made it attack the Astartes. The cogitator purged the intrusion, but Lox realized an enemy had infiltrated the ship.

• Tassa recalled the Salamanders’ devastating battle against Iron Men and warned Lox to remain vigilant around artificial intelligence.
• Lox noticed that the holographic Terra showed nine continents, though his memories alternated between six and nine.
• Lox diagnosed the cogitator and found a tiny code sequence that had spread through its thought engine and distorted its judgment of who counted as human.
• The cogitator classified Nykona and Tassa as non-human and prepared arc weapons to kill them, but Lox ordered it to stop before it fired.
• The cogitator isolated and destroyed the abnormal code, and Lox suspected a Warp entity had infiltrated Prometheus.
• Nykona asked what had happened, and Lox warned him that enemies were aboard the ship.

Nykona and Tassa fought off the Changeling after it impersonated Iron Father Wayland aboard the Red Alert. Four days later, the ship emerged from the Warp near Calth, where Nykona recognized Macragge’s Honour and realized they had reached the Five Hundred Worlds.

• The Changeling impersonated Iron Father Wayland and approached Lox, but Nykona recognized the deception and severed its arm.
• Nykona and Tassa fought the Changeling with their power sword and hammer, cutting it apart as it escaped in eerie laughter and flames.
• Nykona warned Lox that the creature was a Warp daemon, and the real Iron Father ordered the crew to stay vigilant.
• After four more days of Warp travel, the Red Alert emerged in a star system and approached the thriving planet Calth.
• Nykona identified Macragge’s Honour as a Gloriana-class battleship of the Ultramarines and declared that they had reached the Five Hundred Worlds.

Lox and his allies reached Calth but distrusted the Ultramarines, so they began gathering intelligence before revealing the betrayal at Isstvan V. Nykona infiltrated a battleship while Lox, Wayland, and Tassa landed on the planet disguised as Ultramarines, where they were approached by Sergeant Bovi Herlock.

• Wayland warned Lox not to tell the Ultramarines about Isstvan V because he suspected Guilliman and feared another betrayal.
• Lox decided to investigate Calth’s warships and industrial activity without exposing the Red Alert, which the Cogitator cloaked from detection.
• Nykona entered a nearby battleship through the Red Alert’s teleportation matrix to gather intelligence and keep in contact with Lox.
• Lox, Wayland, and Tassa teleported to Calth’s surface, leaving the other Iron Hands aboard the Red Alert in reserve.
• Lox and the Astartes disguised themselves as an attendant and Ultramarines, then Sergeant Bovi Herlock approached and saluted them.

Lox learned that the Ultramarines and Word Bearers were gathering on Calth to fight the Orks, while the locals knew nothing of the Warmaster’s rebellion or Isstvan. He tried to warn Ultramarines command, but Warp interference cut off his connection, so he ordered Herlock’s soldiers to take them to the nearest Ultramarines camp.

• Lox questioned Sergeant Herlock about the planned operation against Greenskin Orks in the Gaslac region.
• Herlock said the Warmaster had ordered the Ultramarines and Word Bearers to muster together on Calth to reconcile an old dispute.
• Lox, Wayland, and Tassa suspected the Word Bearers were preparing to betray the Ultramarines, while Herlock’s lack of knowledge suggested the locals had not heard of the rebellion or Isstvan.
• Lox ordered the Cogitator to infiltrate Macragge's Honour and warn Ultramarines command, but Warp interference severed his connection to the ship.
• Lox demanded that Herlock take them to the nearest Ultramarines camp, and Herlock led his soldiers toward Numenas City after an Astartes confirmed the order.

Lox and his companions encountered Ultramarines Captain Ventanus on the road to Numenas and warned him that the Word Bearers were traitors. As Ventanus raced to alert the Legion, Lox’s group continued toward the assembly point and saw forty-seven Titans marching there.

• The Cogitator reported that Warp interference was being removed and its matter deployment function had been restored, though its teleportation array remained under repair.
• During a storm, Wayland spotted an approaching Ultramarines Land Speeder, and Lox signaled the convoy to stop and meet it.
• Tassa and Wayland revealed their identities and warned Ventanus that the Word Bearers and other Legions had betrayed the Emperor and that the Ultramarines were in danger.
• Ventanus believed their oath, then left with Seraton to relay the warning to the Legion’s high command.
• Lox’s group continued toward Numenas and passed a column of forty-seven Titans marching toward the assembly point.

Lox and his companions warned Ventanus that the Word Bearers posed a grave threat, prompting Calth’s defenders to mobilize. As the orbital Watchtower tried to alert the fleet, hidden Chaos codes activated and began corrupting Calth’s network.

• Lox’s group reached the Universal Museum and relayed the Word Bearers’ threat to Ventanus.
• Ventanus ordered Calth’s forces and orbital defenses to prepare for combat and halt fleet assembly.
• Lamiad praised Ventanus and warned that the Ultramarines would burn the Perfect City again if the Word Bearers betrayed them.
• Hurst received the combat-readiness order and prepared to notify Macragge’s Honour and the other warships.
• The eight Chaos codes hidden in Calth’s mind-space activated, spreading the Warp’s power through the system.

Chaos Scrapcode overwhelmed Calth’s cognitive space, killing Hurst and prompting him to use the Weapon Array to attack Macragge’s Honour. Guilliman’s flagship suffered a laser strike and a devastating Data Surge, leaving its systems in crisis.

• Hurst ordered warships that could receive the Watchtower’s signal to start their engines and leave the spaceports.
• Chaos Scrapcode unleashed a Data Surge that killed dozens of technicians, and Hurst used his final moments to command the Laser Array to attack Macragge’s Honour.
• Guilliman ended his virtual meeting with Lorgar Aurelian shortly before Calth’s Weapon Array struck the flagship and breached its outer armor.
• Guilliman demanded a report as the crew investigated the attack, and the Senior Tech-priest linked it to the Chaos Scrapcode.
• A second Data Surge from Calth overloaded Macragge’s Honour’s cogitators and destroyed Servitors, though the Machine Spirit blocked most of the impact.

After a Data Surge crippled Calth’s communications and disrupted the XIII Legion, Guilliman realized the surface was trying to warn him that the fleet was vulnerable. The cultist-controlled transport Bell Tower then rammed the orbital shipyard and fleet, causing catastrophic destruction and sending wreckage crashing toward Calth.

• Guilliman restored order aboard Macragge's Honour and ordered the crew to bring its shields online and assess the other warships.
• After seeing damage across Calth, Guilliman realized the Weapon Array was trying to deliver a warning, but he could not determine the threat.
• Macragge's Honour detected the Bell Tower accelerating toward Calth with its engines and void shields at full power.
• Chaos cultists aboard the Bell Tower sacrificed the crew and declared their attack in the name of The Empyrean.
• With its weapons offline, Macragge's Honour could not stop the Bell Tower as it tore through the orbital platform and fleet.
• The Bell Tower destroyed Calth Veridian Anchorage, triggered explosions aboard multiple ships, and sent wreckage plunging toward Calth.

Nykona Sharrowkyn infiltrated the Samosores and watched Word Bearers officer Chorl meet Ultramarine Luciel, suspecting the reunion was a deception. Chorl hinted at the Word Bearers’ devotion to the Empyrean and described betrayal as a power that had destroyed three legions, leaving Nykona ready to strike.

• Nykona moved through the Samosores’ lower decks, killing mortal servants to extract memories and trace the Word Bearers’ corruption.
• Nykona spotted Chorl meeting Luciel on the observation deck and watched them greet each other as brothers.
• Luciel questioned the Word Bearers’ new armor and markings, and Chorl claimed he despised Lorgar and had found a new path to the Empyrean.
• Chorl said he had learned unusual techniques of war on Isstvan, drawing Luciel’s interest with talk of a conflict the Ultramarine had never heard about.
• Chorl described betrayal as a force that had destroyed three legions, and Nykona tightened his finger around the trigger while waiting for him to expose his deception.

At a feast between the Ultramarines and Word Bearers, Sorot Chor revealed that his warnings about betrayal were real and launched a surprise attack on Luciel. Nykona’s intervention saved Luciel from the plasma shot, but the Word Bearers escaped as Calth’s orbit erupted in explosions.

• Chor told Luciel he had joined a new path and needed to prove his devotion, and Luciel realized the Word Bearers were betraying them.
• Chor fired his plasma pistol at Luciel, but Nykona shot Chor’s arm and deflected the blast, leaving Luciel badly wounded.
• The Word Bearers opened fire, killing more than ten Ultramarines before the survivors dragged Luciel behind cover.
• Nykona attacked the Word Bearers, while Chor ordered his men to cover his retreat into the chamber’s depths.
• Nykona joined the surviving Ultramarines, and Luciel ordered them to notify the Primarch that the Word Bearers were traitors.
• Explosions near the Orbital Platform stunned the survivors as Calth’s orbit burned.

Numenas suffered catastrophic bombardment as warships and orbital docks fell from the sky, while the survivors in the Universal Museum sought shelter and prepared to regroup. Lox restored communications, allowing Ventanus to report the Word Bearers’ betrayal to Guilliman aboard Macragge's Honour.

• Warships exploded over Numenas, and falling wreckage devastated Calth and sent boiling floods toward the city.
• Ventanus led survivors into the Universal Museum’s underground shelters, where Lamiad and Ventanus planned to gather the scattered Ultramarines.
• Abut told Ventanus about sealed transmitters at the spaceport, but Lox offered to restore communications himself.
• Lox used the Red Alert’s Cogitator to bring a powerful transmitter and Iron Hands into the shelter, then cleared the Chaos Scrapcode interference.
• Ventanus contacted Guilliman aboard Macragge's Honour and confirmed the Word Bearers had betrayed them.
• Guilliman questioned whether the betrayal was confirmed and wondered why Lorgar had acted against them.

Guilliman learned that Horus had betrayed the Emperor as the Word Bearers attacked Calth. Ventanus and the Ultramarines rescued survivors and fought their way to the port, where they clashed with Word Bearers in a close-range firefight.

• Lox told Guilliman that Horus had betrayed the Emperor and destroyed three loyalist Legions at Isstvan, while the Word Bearers fleet opened fire and ended the communication.
• Ventanus led the Ultramarines and Iron Hands out of their shelter to attack the Word Bearers’ mortal cultists and rescue survivors.
• Ventanus sent survivors to the Universal Museum and continued toward the port with volunteers to search for more people and gather forces.
• Ventanus spotted three squads of Word Bearers approaching the port’s control tower and fired first, starting a close-range firefight between the Space Marines.

The Ultramarines and Iron Hands fought back against the Word Bearers on Calth while Guilliman confronted Lorgar during the devastating space battle. Lorgar declared that the Imperium and the Emperor’s dream would fall, as Guilliman’s fleet continued to suffer losses.

• Deputy Seraton and the Ultramarines withdrew as Word Bearer fire destroyed their tower, and the wounded Ventanus called in support.
• Wayland led the Iron Hands in a nuclear missile barrage that vaporized the Word Bearers’ attacking force.
• The Word Bearers fleet ambushed Ultramarines ships in low orbit, destroying the Sacred Saramanth as Guilliman tracked the losses.
• Guilliman accepted a communication from Lorgar and angrily accused him of unleashing the Chaos Scrapcode and causing Calth’s destruction.
• Lorgar declared that Calth was a sacrifice that would usher in a new order, and said the Emperor and the Imperium would fall.

The Word Bearers caught the Ultramarines fleet helpless, destroying nearly half its ships before Guilliman’s vessels restored power and fought back. Lorgar revealed the wider primarch betrayal, then unleashed a Warp creature that swept Guilliman into space.

• The Seventeenth Legion destroyed many Ultramarines warships while their systems were still coming online.
• Macragge's Honour restored its weapons and destroyed the Word Bearers warship Purifying Flame, as other Ultramarines ships regained power and joined the battle.
• Guilliman learned from Lorgar that Horus and numerous other primarchs had sided with The Empyrean, and that Lorgar intended to destroy the Ultramarines.
• Lorgar transformed into a Warp creature and unleashed it aboard Macragge's Honour, sweeping Guilliman into space.

Ventanus led Ultramarines through Calth’s ruined streets, fighting Word Bearers and searching for a way to keep the survivors mobile. After Adeptus Mechanicus Secutarii arrived and requested supplies, Ventanus agreed to lead them to the Universal Museum stronghold.

• Ventanus’s squad passed through tunnels filled with civilian and Ultramarine dead, whose bodies the Word Bearers had desecrated.
• The Ultramarines fought a Word Bearers ambush, losing Brother Atani to a sniper before Ventanus killed the hidden attacker.
• Ventanus’s squad brought down a warehouse and crane onto an attacking Land Raider, but it crawled free.
• Adeptus Mechanicus Secutarii destroyed the Land Raider and killed the surviving Word Bearers with plasma and green beams.
• Aruka introduced himself as a leader of the Calth Secutarii Cohort and told Ventanus they needed supplies.
• Ventanus agreed to lead the Secutarii through the breakout point to the Universal Museum stronghold.

As Calth’s civilians sought shelter from the Word Bearers’ assault, Lox and the Salamanders Apothecary Tassa saved Alina and her baby during a dangerous birth. Holding the newborn, Lox felt his bond with the people of Calth and understood why he fought.

• Calth’s civilians crowded into the Universal Museum as able-bodied adults joined the auxiliary forces to resist the Word Bearers and their cultists.
• Alina went into obstructed labor, and the old woman helping her could not safely deliver the baby.
• Lox called Tassa, who used medical equipment to perform a cesarean section and save Alina and her newborn daughter.
• Tassa handed the baby to Lox while he sutured Alina’s wound, and the civilians cheered the mother and child’s survival.
• Lox returned the baby to Alina and promised that everyone would survive, then felt his connection to Calth’s people and understood why he fought.