But if the violent seismic activity caused by the apocalypse cannon's blast had seemed terrible, it was as nothing compared to the devastation that came in its wake.

It was as if all sound was sucked into the crater that had been created by Gehenna's cannon, for the briefest moment, only to be replaced seconds later by a subsonic whomph that passed through everyone and everything within a ten kilometre radius. And this was only the atmospheric pressurising precursor to the Shockwave that was coming.

Whatever it was that Arch-Magos Schrodinger had ordered the destruction of had been an artefact of immeasurable eldritch power. Waves of green energy doppled outwards from the epicentre of the ordinate's strike, rolling across the ravaged landscape in a wave-front a hundred metres high. The bow-wave consumed all before it. Troopers, both loyalist and traitor, were vaporised where the coruscating tidal wave touched them. The only combatants who were safe from the devastating attack were those who had been able to take cover within dugouts and sheltered trench formations, but even they suffered terrible burns from the heat-wash that subsumed them.

Manufactory sheds were flattened, tanks were thrown kilometres away to come crashing down amidst the trenches of the battlefield outside the ancient war engine itself. Chaos creatures were eradicated, men died. Nothing was left whole as the bow-wave of rippling energy ate up all before it, bathing Fornax Orbis Majoris in its deep-ocean glow; nothing but scorched earth was left.

And there was something else. Shapes flickered and capered in the retina-searing light. Those hypnotised by the roiling energy field before it consumed them, believed they could see eldritch creatures writhing within the explosion of light from the epicentre of the blast.

After forty-two seconds the Shockwave hit the mighty Omnissiah's ancient leviathan Gehenna. The esoteric energy beams blasted through the gaping holes torn in the damaged hull as the massive war machine rocked under the phenomenal battering. Those not protected inside the undamaged parts of the ordinatus were killed just like the Chaos forces who had sought to unleash the same terrifying power to further their own ends. Two hundred and fifty-six tech-priest adepts, crew ratings and tech-guard troopers died, immolated by the atomic heat of the all-destroying energy waves. Not one Iron Hand was killed.

The blast was registered by the Imperial commanders buried within the bunker command post of Ferroturitus Prime Guard HQ, the lights going out for twenty seconds and dust falling from cracks that appeared in the ruptured ferrocrete ceiling.

It was even detected by the Iron Hands' strike cruiser waiting in geo-stationary orbit above the northern land mass of the poisoned forge world. The dissipating energy waves buffeted the Ajax, causing a drop in operating efficiency of thirty-three per cent across its void shields, and knocking out ship-to-planet comms that were not restored for another six minutes.

The released energy continued on and out into the black void, drawn inexorably towards the roiling boundaries of the distant, red-tinged gaze of the Eye of Terror.