Dark, the sky; acid wind howling, scouring bare the bones of the fallen guardsmen. Nothing of human flesh remained alive on the tortured ground where the Imperials had fought and died; overwhelmed at last by the endless wave of tearing teeth and rending claw. Now, the Tyranid Hive having reabsorbed its lethal progeny, only wind-blown detritus moved. The Hive sought to change the world, to absorb it. Change the world would; but not in the way the Hive-mind planned.

Ferumbras, dead a thousand years and more, yet living on in his sarcophagus, resurrected by the arts of apothecary and techmarine, listened to the seething discontent of his ancient tomb. The dreadnought-shell, a semi-sentient plasteel-and-ceramite fortress, more ancient even than Ferumbras himself, remembered the Emperor in all his glorious fury upon the battlefield, and itched to come to grips with the xeno-foe; to cleanse with flame, to shatter with canon-fire, to crush in its metal fist, the grotesque organic towers the Tyranid had grown. But Ferumbras was old in war, and wise; he knew the wisdom of patience and ignored the siren call to action of his grumbling shell.

When the final battle was clearly lost and the massed regiments of the guard broken into screaming hordes of panic (though a stalwart few had fought on undaunted around their standards, and Ferumbras admired the frenzied courage of those few, as he understood the weakness of mind that had made most seek salvation in hopeless flight even when there was nowhere left to flee), Ferumbras’ brothers had made a disciplined retreat behind a rearguard of their oldest, most venerable dreadnoughts: veterans who had seen millenia of war, grim and fearless. They would march no more, their surrogate bodies torn to fragments at last by the unending tide of Xeno-spawn. The countless Tyranid they had killed were of no significance now the planet was lost – but the chapter would long rue their own losses, such experience and strength were irreplaceable.

The chapter-master’s iron voice had spoken as the last of the marines had boarded the final Thunderhawk Gunship and took to the storming skies, weathering a hail of acid fire from the Xenos and screaming away into space. ‘Hold fast, brother; we will return when we can, or avenge you.’ And Ferumbras, last of the Venerable dreadnoughts, roared the chapter war-cry and fought on alone, hearing his departed brothers echo his shout, hundreds of voices raised as one to salute him.

Relentless, he had fought his way to the fluted cliffs that men called The Sacred Wall, a towering mass of granite that fell ten thousand meters from its ice-bound summit scarp to the blasted plain beneath. There he wedged in a cave, back protected by the immensity of rock and held his ground. When his ammunition was gone: the last cannon-shell fired, the flamer fuel spent, he battered the Xenos, meeting claws and fangs with the lightning-crackle of his giant fist. Soon the Tyranids were boring through a mound of their fallen to come at him; at last they failed, the Hive-mind recalled its spawn and Ferumbras waited, patient in rancour, as the planet changed.

Days passed. Weeks. Ferumbras waited and watched, knowing his brothers would come. And now they do, the thunderous engine-howl, drowning the wail of the acid wind. Ferumbras signals, registering his position with the chapter-fleet. No living brother is abandoned. The chapter-master himself replies, ‘Well fought, brother. I salute you and am sorry.’ The sky explodes in the white-hot flame of Exterminatus.

Ferumbras replies before he dies: 'No apology necessary. You came back.'