'What in Terra's name is that fool up to?' Temeter snarled. 'Raise the Titan! Get Princeps Turnet on the vox and have him explain himself!'

The captain of the Fourth Company scanned the hull of the machine with his optics. There was no visible damage of such scale that would cause a Titan to shut down, no possible reason that Temeter could see for it to just stop. His line of sight passed over the access hatches in the hull and he saw all of them were shut fast. Temeter searched for and found power shaft

vents in the thigh armour of the mechanism. Normally they would be puffing with the release of spent coolant gasses, but instead they were sealed. Chill knives of apprehension stabbed into him.

'I can't raise the Dies Irae', said the other man. "Why don't they answer? They must be able to hear us!'

'A bio-weapon.' Temeter reached up and checked the seals at his neck, a creeping sensation of trepidation coming over him. The captain's head tipped back, his gaze moving to take in the yellowish sky over the Titan's huge iron shoulders. He saw twinkling glitters up there, streaks cutting through the upper atmosphere with trails of white vapour behind them. The sight shocked him into action. 'Squad-wide comms, now!' he shouted. 'All Death Guard disengage and seek cover! Bio-war alert! Make for the bunker complex to the west.'

The other Astartes relayed his orders into the vox even as he and Temeter broke from their meagre cover.

Temeter saw the dreadnought Huron-Fal turning in place. 'Ullis Temeter!' The venerable warrior's synthetic machine-voder was loud and scratchy. 'Who has done this?'

'No time, old friend,' he said on the run. 'Just get the men inside, nowV With every pounding step he took, a part of Temeter's mind was reeling with the import of what was taking place. The bombs were falling, and there was only one person who could have sent them.

GARRO AND DECIUS made it up the ramp to the windowed gallery overlooking the barracks chamber in time to witness the ships of the Warmaster's fleet open fire on Isstvan III. A myriad of silver streaks,

almost too fast to see with the naked eye, streamed over and around the Eisenstein and the other smaller ships at low anchor above the Choral City. Although they were just blurs, Garro didn't need to see them clearly to know what they were: Atlas-class heavy warheads converted for space-to-surface functions, servitor-guided missile bombs and multiple impact penetrator munitions. It seemed as if only Eisenstein's guns remained silent, as if every capital ship in the 63rd Fleet were taking some part in the brutality. The bombs came in a solid rain of murder, falling fast, turning and converging towards pre-designated target points all across the planet. From this terrible god's-eye view of the onslaught, the distant grey-white patch upon the main continent that was the Choral City was easily visible.

Garro watched in abject horror as the instruments of Horus's betrayal flared red as they punched through the atmosphere and fell upon his battle-brothers. At his side, Decius's face was rapt with a peculiar, grotesque fascination as he struggled to comprehend the magnitude of the destruction.

TEMETER AND HURON-FAL were at the shallow ridge before the bunker's steel hatch, shouting at their kinsmen to run and run, to ran and not look back. Temeter felt a pang of fear, not for himself, but for his men. They had responded perfectly to his command, falling back in good order and surging away from the enemy along the trench lines they had already cleared. Hundreds of them were already in the bunkers, sealing themselves in to weather the imminent bombardment, but there were many more he knew would not live to make it to the doors. He looked up again at the sickly sky and Temeter became

torn inside. Who betrayed us, he asked himself, echoing the aged dreadnought's question? Why, in Terra's name, why?

'Ullis!' barked the old warrior, stomping to his side. 'Get in there! We have only a few seconds!'

'No!' he retorted. 'My men first!'

'Idiot!' growled Huron-Fal, throwing protocol to the wind. 'I will stay! Nothing will be able to crack my hide. You go, now!' He shoved Temeter with his colossal manipulator claw. 'Go inside, damn you!'

Ullis Temeter stumbled back a step, but his gaze was still on the sky. 'No/ he said, just as flickers of brilliant light turned the day a glittering white.

At high altitudes overhead, the first wave of the virus warheads detonated in series, a wall of airbursts instantly unleashing a black rain of destruction. The viral clades, capable of hyper-fast mutational change and near-exponential growth rates, feasted on native airborne bacteria. The thin, dark bloom of the death cloud rolled out over the Choral City, just as the second wave fell. The shells did not explode until they hit the ground, bursting to smother city districts, open fields and trench lines with tides of destructive haze.

The Life-Eater did as it had been engineered to do. Where a molecule of it touched an organic form, it spread instant, putrefying death. The Choral City, every living thing, every human, animal, plant, every organism down to the level of microbes was torn apart by the virus. It leapt boundaries of species in a second, burning out the life of the planet. Flesh rotted and blood became ooze. Bones shredded and turned brittle. Isstvanians and Astartes alike died screaming, united in death by the unstoppable germs.

Temeter saw the warriors running towards him, dying on their feet. Figures fell to the mud as their corpses turned to a red broth of fleshy slurry, viscous fluids seeping from the chinks in their power armour. He knew that he had dallied too long, and he shouted with all his might. 'Close the hatch. Close it!' The men in the bunker did as he told them, even as he tasted blood in his mouth and felt his skin prickling with budding lesions. The metal door slammed shut and hissed with a pressure seal, locking him out. Temeter hoped they had been quick enough. With luck, they would not have taken any of the virus inside with them. He managed two stumbling steps before he fell, the muscles in his legs singing with agony.

Huron-Fal caught him. 'I told you to ran, you fool.'

The captain flung off his helmet with a final, agonised gesture of defiance. It was useless now, the virus having moved effortlessly through the breather grille and into his lungs. His hand flailed at the metal flank of the dreadnought and traced a runnel of dark fluid. Even through the pain, Temeter understood. There was a small fracture in the old warrior's ceramite casing, not enough to have slowed him on the battlefield, but more than the virus needed to reach inside the dreadnought's hull and savage the remnants of flesh inside. 'You... lied.'

'Veteran's prerogative,' came the reply. 'We'll go together then, shall we?' Huron-Fal asked, embracing Temeter's body to him, moving swiftly away from the bunker.

It took every last effort from Temeter to nod. Blinded now, he could feel the tissues of his eyes burning and shrivelling in his head, the soft meat of his lips and tongue dissolving.

Huron-Fal's systems were on the verge of shutdown as he stumbled to a safe distance, skidding to a halt. This death,' rasped the voder, 'this death is ours. We choose it. We deny you your victory.'

With a single burning nerve impulse, the mind of the warrior at the heart of the dreadnought uncoupled the governor controls on his compact fusion generator and let it overload. For a moment there was a tiny star on the battered plains outside the Choral City, marking two more lives lost within a maelstrom of murder.

GARRO TURNED AWAY from the blossom of darkness across the dying world and glared at his protege. 'Now do you believe it? With a planet scoured of life before your eyes, do you have proof enough of this madness?'