Chapter Summaries

The Emperor warned Lox that Horus had become a vessel for the four Chaos Gods and that he might not be able to defeat him. He revealed that absorbing Warp energy could let him contend with Horus, but warned that doing so without restraint would awaken the Dark King, then admitted he had already begun absorbing energy with limits.

• The Emperor told Lox that Horus had gathered his forces at Ullanor and that the rebels were advancing toward Terra.
• The Emperor and Lox visited the genetic engineering laboratory, where Arkhan Land, Belisarius Cawl, and other sages studied an original template.
• The Emperor explained that Horus had lost the last goodness in his soul and could now wield the full power of the four Chaos Gods.
• The Emperor said he could gain enough power to challenge Horus by absorbing Warp energy, but warned that unchecked absorption would awaken the Dark King.
• Lox realized the Emperor had already begun absorbing Warp energy with limits and confronted him about it.

Lox learned that the Emperor had once had another choice between resisting Horus without Warp power and risking the birth of the Dark King. Malcador and Oll Persson arrived to warn the Emperor against using Warp energy, and Oll’s reunion with Neoth left their old bond and estrangement unexplained.

• The Emperor told Lox that the Chaos Gods had forced him into a second dilemma: absorb Warp energy to fight Horus or rely on his own strength.
• Malcador arrived on Ganymede and urged the Emperor not to devour Warp energy, warning that the Dark King’s birth would doom humanity.
• Oll Persson arrived with Malcador and told Neoth to stop as well, prompting a tense reunion with the Emperor.
• Malcador explained that Oll was an ancient Perpetual, the Emperor’s first Warmaster, and his longtime companion in events including the fall of the Tower of Babel.
• Lox learned that Oll had lived on Calth before the Word Bearers destroyed his farmland, though he and Oll had never met there.

Oll Persson met with the Emperor and refused to return as Warmaster, warning that the Emperor had already begun turning into a god. He explained that the power within the Emperor embodied endings and death, and would drive him to destroy all life.

• Oll Persson recalled his ancient friendship with the Emperor and said he was tired of war and wanted to farm on Calth.
• The Emperor asked Oll Persson to return and help humanity, but Oll Persson showed little interest in becoming Warmaster again.
• Lox remarked that Horus had been a substitute for Oll Persson, whose farming mattered more to him than the title of Warmaster.
• Oll Persson said he had returned to stop the Emperor from doing something foolish, then revealed that a ritual dagger had shown him the Emperor had already begun becoming a god.
• Oll Persson warned that the power within the Emperor embodied endings and death and would eventually compel him to destroy every being in the universe.

The Emperor tried to persuade Oll Persson through a Custodian, but Oll exposed his secret use of Warp energy. Lox and Malcador recognized the danger and resolved to stop the Emperor from pursuing apotheosis.

• The Emperor summoned a Custodian to debate Oll Persson and invite him to return, while Lox saw through the Emperor's attempt to hide behind his guard.
• Oll Persson told the Custodian that Malcador, Erda, John, and an Aeldari seer had helped bring him to Terra.
• Oll Persson used his ritual dagger's reflection to reveal the dark sphere above the Emperor and accused him of drawing in Warp energy.
• The Emperor accidentally admitted through the Custodian that he was absorbing Warp energy to strengthen himself against Chaos and Horus Lupercal.
• Lox and Malcador agreed that they had to stop the Emperor from moving toward apotheosis.

Lox, Oll Persson, and Malcador confronted the Emperor and urged him to stop absorbing Warp energy to defeat Horus. The Emperor fell silent as they challenged him to face Horus as a human, leaving his choice unresolved.

• Malcador sent away the Custodian decoy, and the Emperor insisted that he needed Warp energy to defeat Horus and the Four Gods.
• Oll Persson reminded the Emperor that he had once stopped him from excavating the power of the Dark Tongue, and threatened to stab him again if necessary.
• Malcador and Lox threatened to abandon the Emperor and leave Terra if he refused to turn back.
• Lox warned that absorbing Warp energy could make the Emperor the Dark King and doom humanity, while Oll described a parallel timeline ending in universal destruction.
• Oll removed his cross necklace and challenged the Emperor to abandon Warp power and confront Horus with humanity's strength.

The Emperor stopped drawing power from the Warp and fought Horus Lupercal’s gray wolf projection, explaining that he had sacrificed everything to help humanity survive. After confronting Horus and the four Chaos gods, he returned his attention to Oll Persson, Lox, and the others, saying the trouble was dealt with for now.

• The Emperor promised Oll Persson, Lox, and Malcador that he would not cross the line again, then turned his attention to a problem in the Warp.
• Horus Lupercal’s gray wolf attacked the Emperor’s black sun projection and accused him of deceiving humanity and exploiting the Warp.
• The Emperor admitted that the Imperial Truth was a lie, but said he had used it to protect humanity and had treated himself and his sons as tools for its survival.
• Horus attacked more fiercely as the Emperor defended himself and told the four Chaos gods that they were too weak to oppose him directly.
• Neos returned to the conversation with Oll Persson and the others, saying the trouble had been dealt with for now.

Lion El'Jonson and the Loyalist commanders assessed the forces gathered to defend Terra as Guilliman's army fought through rebel territory. They identified Pluto and Uranus, home to the Twin Gates, as the rebels' likely targets and began planning a trap around them.

• Lion El'Jonson, the primarchs, and their allies reviewed the Loyalist forces assembled in the Solar System, which numbered about three hundred and fifty thousand Space Marines.
• Lion received Guilliman's message that his Legion had about three hundred thousand warriors and was pushing through the rebels' rear lines.
• Lion told the commanders they could not wait for Guilliman because the rebel spearhead had already reached the Solar System's outer defenses.
• Sukasan remarked on Lion's reputation, and Lion answered with jokes that eased the meeting.
• The commanders identified Pluto and Uranus as the rebels' likely attack points because they held the Gate of Hades and the Gate of Elysium.
• Lion and the commanders prepared to build their first strategic trap around the Twin Gates.

The loyalist leaders debated how to defend the Gemini Gate and agreed to turn it into a trap for the rebels. After considering who might command Horus’s forces, they identified Perturabo as the likeliest commander and assigned Lion and Dorn to prepare the defense.

• Admiral Sucasan proposed destroying the Gemini Gate, but a Tech-priest objected that doing so would damage morale.
• Dorn proposed using the Gemini Gate as bait for an encirclement-and-reinforcement trap, while the Khan warned that Horus might attack somewhere unexpected.
• Sevatar argued that Horus might not command the rebel forces because he had been compromised, prompting the leaders to reconsider their assumptions.
• Jaghatai ruled out the other likely rebel primarchs, and Dorn concluded that Perturabo was the most probable commander.
• The leaders voted to concentrate forces at the Gemini Gate, and Lion assigned himself and Dorn to prepare its defenses and trap.

Sigismund inspected Pluto’s defenses and questioned mortal soldiers about their willingness to die for Terra, while reflecting on his exile and strained relationship with Dorn. When Warp rifts appeared in space, he drew his sword and ordered the defenses to prepare for the enemy’s arrival.

• Sigismund inspected a battlefield fortress and asked Wade Dalton why the soldiers accepted being the first to die.
• Wade explained that he and his comrades felt fear but had accepted thought-stamp implantation to serve as Terra’s first line of defense.
• Sigismund left the soldiers after their answer improved his mood and reflected on how he had been banished to command the Pluto Defense Zone.
• Sigismund recalled Dorn’s rebuke and his pain at being separated from his primarch.
• Warp rifts appeared in space, and Sigismund drew his power sword and ordered everyone to alert status.

Horus's forces broke into the Solar System through Pluto and Neptune and launched a massive assault on Imperial defenses. Sigismund watched the battle rage around Pluto and foresaw a future of unending war.

• Sigismund returned to Pluto's command center after the Warp anomaly revealed that the traitors had entered near Pluto and Neptune, bypassing the Mandeville Point defenses.
• More than a thousand rebel warships attacked Imperial fortresses and defenses, destroying a fortress and killing its Imperial Fists garrison.
• The Imperial counterattack began with automated Cogitator targeting, massed torpedoes, and space mines produced through Lox's expanded factories.
• Imperial fortresses advanced against the rebel fleet as both sides suffered enormous losses and more enemy ships emerged from the Warp.
• Sigismund watched the battle and realized that the galaxy would know only war in the distant future.

Sigismund embraced his role as commander of Pluto’s defenders and rallied them as rebel forces launched an orbital assault. He led his Imperial Fists into battle to protect Pluto’s defenses from the Sons of Horus.

• Sigismund ordered the Tech-priest to connect every battlefield communications channel and became a cold, focused symbol for the defenders.
• He told the Imperial forces, “For the Emperor! For humanity!” and inspired them to fight without retreat.
• Sigismund recognized the Sons of Horus’ drop pods and realized the rebels aimed to capture Pluto and Neptune intact by decapitating their command.
• He chained his greatsword to his wrist and led Fafnir Rann, Pollux, and his guard toward the battlefield to protect Pluto’s defensive installations.
• The defenders noted that the traitors had begun their orbital assault before destroying Pluto’s warships and defenses, and prepared to make them pay dearly.

Sigismund received Rogal Dorn’s order to hold Pluto while secretly withdrawing the orbital defenses and preparing to destroy the Gates of Hades. As the Imperial Fists retreated, Little Horus Aximand pushed the Sons of Horus toward Pluto and prepared to lead a decapitation strike against Sigismund.

• Rogal Dorn ordered Sigismund to make the defense of Pluto appear desperate while withdrawing the forces guarding the warp gates and preparing to detonate them.
• Sigismund ordered the Imperial Fists fleet to retreat under heavy fire, with escort ships sacrificing themselves to cover the withdrawal.
• Little Horus Aximand rejected Forrix Braun’s demand to pursue the Imperial Fists and instead prioritized capturing Pluto as a bridgehead.
• Aximand allowed Forrix to take a third of the fleet after the fleeing Imperial Fists, while ordering the rest to attack Pluto’s defenses.
• Aximand ordered an orbital drop with the elite Gasterlin Terminators to kill Sigismund as the Sons of Horus bombardment overwhelmed Pluto’s defenses.

Aximand led the Sons of Horus invasion of Pluto, aiming to destroy the Imperial defenses and kill Sigismund. Sigismund cut through the traitors until he and Little Horus faced one another and charged into battle.

• The Sons of Horus used Chaos sorcery to disable Pluto’s automated defenses and slaughtered the Imperial defenders near their landing zone.
• Aximand arrived with Gasterlin Terminators and ordered his forces to find Sigismund and cut off his head.
• The Sons of Horus and their allies destroyed Imperial supply depots, ports, and fortresses as they advanced toward the command center.
• Sigismund and his Imperial Fists engaged the invaders, and Sigismund rapidly killed the Sons of Horus who attacked him.
• Aximand reached the battlefield with his Gasterlin Terminators, and he and Sigismund charged at each other.

Sigismund fought through the Sons of Horus assault on Pluto, cutting down wave after wave of attackers before facing Little Horus. He defeated Aximand, who escaped by teleporting to his orbiting warship, leaving Sigismund to confront the remaining Sons of Horus.

• Aximand led Gasterlin Terminators against Sigismund, whose Imperial Fists comrades fell under their daemon-empowered bolter fire.
• Sigismund charged Aximand, deflecting incoming shots and severing enemy weapons as he fought through the attackers.
• Aximand abandoned the idea of a fair duel and joined his Terminators in surrounding the exhausted Sigismund.
• Little Horus pressed his attack and wounded Sigismund, but Sigismund evaded his headbutt and severed his right hand.
• Sigismund pierced Aximand's chest, but Aximand teleported away to his warship before Sigismund could finish him.
• Sigismund turned toward the remaining Sons of Horus, ready to continue fighting.

Sigismund and the Imperial Fists struggled to hold their position on Pluto against the Sons of Horus while waiting for reinforcements. Sage Lox’s Iron Men arrived in overwhelming force, and their leader Adam introduced himself to Sigismund as they turned the battle against the traitors.

• Sigismund defeated Little Horus, then withdrew toward Perius and the Imperial Fists as the Sons of Horus continued their attack.
• Perius, Rann, and Sigismund led the Imperial Fists in holding their shield wall against the traitors’ heavy weapons and daemonic forces.
• As rebel warships entered the battlefield, Sigismund and his warriors wondered where the promised reinforcements were and prepared to keep fighting.
• Metal obelisks fell from orbit and crushed Sons of Horus, then revealed a force of Iron Men emerging through the smoke.
• Adam greeted Sigismund, explaining that Sage Lox had sent the Iron Men to support the Emperor’s loyal warriors.
• The Iron Men unleashed gauss fire and drove the Sons of Horus onto the defensive.

Adam and his Iron Men arrived on Pluto to help Sigismund’s forces withdraw and fight the Sons of Horus, while Adam began destroying the Twin Gates. Adam chose to delay the gates’ destruction so he could trap more enemies, leaving the mission and his growing independence in motion.

• Adam saluted Sigismund and relayed Lox’s command to cover the Imperial Fists’ withdrawal and drive out the Chaos rebels.
• Sigismund asked whether the Twin Gates were ready to be destroyed, and Adam said he had already begun the task.
• Iron Men poured from orbital drop containers and charged into close combat against the Sons of Horus under the central Cogitator’s command.
• Sigismund gathered his surviving Imperial Fists and mortal auxilia and evacuated Pluto.
• Adam halted his elite Iron Man squad inside the Twin Gates’ core plasma reactor, deciding to let the Iron Warriors board before detonating the gates.

Saduran led an Iron Warriors assault through the Cerberus satellite fortress, where Imperial Fists defenses and Adam’s Iron Men killed his squad. Adam took control of the fortress and destroyed it, annihilating hundreds of rebel warships and the Gemini Gates as the true gate to the Underworld opened.

• Saduran led Iron Warriors recruits through the Cerberus satellite fortress, losing several to hidden guns, automata, and combat Servitors.
• Adam’s Iron Men killed Saduran and the remaining recruits with gauss beams.
• Adam seized the fortress’s control system, opened its blast doors, and overloaded its reactor with singularity generators.
• The Cerberus fortress exploded, destroying more than three hundred Sons of Horus and Iron Warriors warships.
• Adam destroyed Nix III, Nix I, and the Gemini Gates in the resulting chain of explosions.
• The true gate connecting to the Underworld slowly opened.

Adam returned from the successful destruction of Pluto’s warp gates and defenses to join Sigismund aboard the evacuation transport. Sigismund ordered a counterattack against the disorganized rebels, with Adam and the Iron Men ready to fight alongside the Imperial Fists.

• Adam destroyed the rebel fleet’s targets on Pluto and preserved the Iron Men’s consciousnesses by uploading their data before their bodies were lost.
• Adam reassembled aboard the evacuation transport and explained to Sigismund that the Iron Men could return in new bodies as long as their data survived.
• Adam argued that humanity should be defined by culture and identity rather than genetics, leaving Sigismund to consider his claims.
• Sigismund recognized the confusion caused among the rebels by the destruction of Pluto’s defenses and ordered the fleet to counterattack.
• Adam tried to bond with Sigismund and the others by bumping Lann’s shoulder, then pledged to follow Sigismund’s orders.
• Sigismund ordered the warships to turn about, maximize engine output, and charge through the rebels.

Sigismund turned the battered Imperial Fists fleet around to attack the rebel vanguard, which had been isolated by the destruction of the Gemini Gates and its satellite fortresses. Aximand ordered Vol Braun to retreat, but Braun ignored him and prepared the Iron Warriors to fight as Aximand rushed to support them.

• Sigismund ordered the Imperial Fists fleet to execute an emergency turn and charge the rebels.
• The Imperial Fists prepared their weapons as the Sons of Horus and Iron Warriors vanguard realized it had been cut off from the main fleet.
• Warsmith Vol Braun recognized the Imperial Fists' ambush, but Little Horus Aximand's order to withdraw failed to change his mind.
• Braun severed communications and committed the Iron Warriors to a fight against the charging Imperial Fists.
• Aximand ordered his fleet to cross the blast zone and support the Iron Warriors.

The Imperial Fists turned the battle against the Iron Warriors, and Adam led an assault on Vollbraun’s flagship. Adam fought through the ship using the Caliban swordsmanship Lion El'Jonson had taught him.

• Sigismund led the Imperial Fists into the Iron Warriors fleet in a wedge formation, and his commanders destroyed the battlecruiser Gorgon of Fire.
• Sigismund found Vollbraun’s flagship and ordered the Templars to launch a strike, but Adam volunteered to lead the assault.
• Adam and the Iron Men boarded a strike cruiser and teleported into the enemy flagship, where some Iron Men reassembled after materializing inside its walls.
• Adam and the Iron Men fought toward the command bridge, and Adam cut down Iron Warriors with his power swords while firing plasma and melta weapons.
• Adam reflected on Lion El'Jonson’s lesson that Caliban swordsmanship allowed any tactic that secured victory.