‘Iron-Father.’ Gdolkin heard Captain Thrask's panting voice over his helmet comm.

'Report your status.’ he returned, his voice cold, hard steel again.

'Generarium controls have been restored to the bridge.'

The heretics' sabotage attempt had been thwarted.

'Magos Schrodinger.’ Gdolkin said, switching to a different channel with a thought, 'power is restored.'

'Thank the Omnissiah, yes!' Arch-Magos Schrodinger declared, his tone euphoric. 'Gehenna is restored to us!'

'Power levels at seventy-seven per cent, and rising.’ the monitoring adept stated. 'Seventy-eight, seventy-nine, eighty-'

'This is your last chance.’ Thule said, stalking towards Schrodinger across the bridge command platform.

'Eighty-one, eighty-two-' ,

The commander of the ordinatus shot his rival a poisonous dart of unashamed hatred. There were no words spoken in defence of his actions now, no recriminations.

'Fire!' Schrodinger spat the word with vehemence, giving the command even in the face of Magos Thule's protests.

The arch-magos's command was relayed throughout the stations of the command nave in seconds. The rising hum of the powering apocalypse cannon became a painful shriek. The ordinatus shook with the barely contained forces pulsing through the ancient machine.

The cannon fired.

Thule screamed.

A pulse of crimson light erupted from the mouth of the enormous cannon, wreathed in coruscating beams of barbed orange lightning, waves of power evaporating to heat and melting the fog of war from above the battlefield accompanied by a hurricane-force wind.

In the distance, still some kilometres away, amidst the stripped bare bedrock of the Argentum Mountains, lay the focus around which the Plague God's forces had gathered like flies around a corpse.

The apocalypse beam cut through the roiling clouds circling above the ragged peaks, burning away the unnatural night that claimed dominion over the mountains in a searing blaze of light that was indeed like the light of apocalyptic oblivion.

The cannon's beam hit the mountainside with all the force of a crashing meteorite. The mountain exploded, shards of rock the size of hive towers splintering away from the face of the target. The foothills of the Argentum range were buried by a tumultuous landslide, sheets of rock plummeting down the mountainsides. Cataclysmic booms shook the spine of the mountain range.

The beam continued to bore its way through the bedrock, into the planet, like a Mechanicus mining machine, the land for a radius of twenty kilometres around suffering seismic disturbances violent enough to topple tall buildings. The very ground beneath great Gehenna shook, so that barely a man was left standing on board the monumental vessel. It felt as if the recoil forces unleashed by the firing of the cannon were going to shake the wounded ordinatus apart.

A great gout of broiling lava vomited skyward as the apocalypse cannon's beam finally punctured a magma vent deep beneath the earth. Whatever lay within the mountains that was of such importance to the Death Guard and the other heretics was buried, destroyed in the volcanic heat of the gushing lava flow. Thousands of ravening cultists and their Nurgle Marine overseers dissolved in the fiery flood that erupted from beneath the planet, as if Fornax Orbis Majoris was at last being avenged upon its pillagers.