Mourning for the loss of his mentor, Reclusiarch Mordred, Grimaldus contemplates on what the Black Templars have in plan for him in the midst of the next Crusade.
Grimaldus receives the rank of Reclusiarch in honor of his late mentor, Mordred and his squad of fellow Templars is introduced, yet he remains skeptical about the occupation of Chaplaincy in his youth.
Black Templars land on the planet Armageddon to meet with the legendary Lord Commissar Sebastian Yarrick for the planet's defense. Grimaldus' eagerness for glory conflicts against High Marshall Helbrecht's pragmatism.
Realizing that the Steel Legion alone may not be enough against the Orks, Grimaldus contemplates for options that can possibly turn the tide in the Imperium's favor as Helsreach prepares for the invasion.
A fallen Astartes Strike Cruiser must be dealt with to prevent being looted by the Orks, but Squad Grimaldus faces not only self-doubt, but also grim tidings from High Marshall Helbrecht.
The Orks return to assault Helsreach with greater strength. Unpertubed by such a vast horde, Grimaldus gives a speech to encourage the defenders to never to be intimidated against a innumerable foe.
Grimaldus searches for a forgotten weapon that was used by the Imperium ages past but risks losing his alliance with Invigilata in the process, inadvertently crossing paths with Steel Legionnaire Andrej Valatok.
Princeps Majoris summons Grimaldus about the discovery of the ancient Mechanicum weapon. When Grimaldus manages to workaround the Princeps' concerns, the Titans of Invigilata are deployed in the defense of Helsreach.
The walls of Helsreach has been breached and the Greenskin invaders pour in, sending the Imperium defenders to immediate disarray unless Grimaldus can rally them to coordinate their defenses.
The defense of Helsreach begins to wear out the Imperium defenders as the Orks intensify their assault with greater strength, threatening to overrun them unless reinforcements can arrive soon.
Weakened by the increasingly powerful Ork attacks, the surviving Imperium defenders gather at the Temple of the Emperor Ascendant for a last stand. Grimaldus is sure he would die in Helsreach, but fate has other plans for him.
