Siege of Terra Books in Order

The Traitors and Loyalists clash in a massive void war across the Solar System. Horus must breach Dorn's defences to reach Terra. Former remembrancer Mersadie Oliton searches for a way back to Terra, while disgraced Sigismund seeks atonement through battle.

Horus now holds the Solar System and begins the bombardment of Terra. To reach the Palace walls, he must overcome ground defences, outer bastions, and the Aegis void-shield. A massive ground war erupts. On the walls, the Loyalists face refugees, embattled defences, and the malefic Warp, while Guilliman races to arrive in time.

With the outer defences fallen, Horus orders Perturabo and the Iron Warriors to seize the Lion's Gate Spaceport from the Imperial Fists. The traitors must overcome the First Wall to claim this vital objective. Meanwhile, Horus tasks his Dark Apostle Zardu Layak with bringing the Daemonic Neverborn of Chaos onto Terra itself.

The Traitors under Perturabo search for weaknesses in the Imperial Palace's defences. Rogal Dorn must make difficult decisions to hold the palace until reinforcements arrive. A struggle for a vulnerable section of the wall called Saturnine will determine whether the palace stands or falls.

SpoilersThe Traitors under Perturabo search for weaknesses in the Imperial Palace's defences. Rogal Dorn must make difficult decisions to hold the palace until Roboute Guilliman arrives. Dorn also creates an order of scholars to record and conceal the civil war's history. A struggle for a vulnerable section of the wall called Saturnine will determine whether the palace stands or falls, while secrets emerge in the palace depths and beyond.

Horus holds the Lion's Gate and Eternity Wall Spaceports. He unleashes the Legio Mortis Titans upon Terra. The Loyalist Legio Ignatum races to meet them at Mercury Wall. Ollanius Persson journeys through the warp toward Terra. Corswain of the Dark Angels plans a desperate gambit beyond the Palace walls.

As the Palace defenses weaken, Jaghatai Khan risks a bold strike to reclaim the Lion's Gate spaceport from Mortarion and the Death Guard. Inside the walls, Dorn wrestles with strategy, Sigismund discovers a new path, Keeler finds a darker perspective on hope, and Valdor hunts amid his own conflict.

Most of the Imperial Palace has fallen to the Traitors. The berserk primarch Angron leads the slaughter through Terra's ruins. With the Khan near death, Dorn hard-pressed at the Bhab Bastion, and Guilliman's arrival uncertain, Sanguinius must gather the defenders for a final stand at the Delphic Battlement and the Eternity Gate.

SpoilersMost of the Imperial Palace has fallen to the Traitors. Angron, elevated to Horus's herald after Mortarion's defeat, leads the slaughter through Terra's ruins. With the Khan near death, Dorn hard-pressed at the Bhab Bastion, and Guilliman's arrival uncertain, Sanguinius must gather the defenders for a final stand at the Delphic Battlement and the Eternity Gate.

Time on Terra has frozen in the Warp, and Horus nears victory. To draw the Emperor into battle, he lowers the defences of his flagship. Ollanius Persson reaches the Palace to warn of Horus's growing power, but the Emperor has already teleported aboard with his sons and warriors. Garviel Loken also makes his way to confront his father.

The Emperor and his warriors are scattered across the Vengeful Spirit as the ship grows saturated with Warp energy. Sanguinius encounters the shade of his fallen brother Ferrus Manus, who leads the Angel toward his final confrontation with Horus. The Blood Angels fight on as their father's fate approaches.

SpoilersThe Emperor has drawn upon the Warp for power to defeat Horus, risking becoming the Dark King himself. Persson and Loken beg him not to become Chaos to defeat it, and he relents, releasing the power he gathered. Sanguinius falls to Horus, who crucifies his corpse in the Lupercal's Court.

The Emperor reaches the bridge of the Vengeful Spirit to confront Horus at last. The Warmaster waits with his final gambit ready, while the Emperor’s surviving sons and loyal warriors fight through the ruined flagship to reach him. On Terra, the Golden Throne stands prepared for what may come.