'Head shots only!' he cried as he put another of the dead things down, its skull a ruin of blackened bone and sloshing ooze. The tide of the battle began to turn as more and more of the shambling horrors went down and stayed down. The green-fleshed things with grotesquely distended bellies took more killing, though it seemed to Loken that they dissolved into stinking matter as they fell into the water of the swamp.

More shapes moved through the mist as a thunderous roar of heavy cannon fire came from behind them, followed by the bright flare of an explosion high above. Loken looked up to see a golden landing skiff trailing smoke and fire wobble in the sky, though he had not the time to wonder what a civilian craft was doing in a warzone as yet more of the dead things climbed from the water.

Too close for bolters, he drew his sword and brought the monstrously toothed blade to life with a press of the activation stud. A ghastly thing of decomposed flesh and rotten meat hurled itself at him and he swung his blade two handed for its skull.

The blade roared as it slew, gobbets of wet, grey meat spattering his armour as he ripped the sword through from brainpan to groin. He swung at another creature, the green fire of its eyes flickering out as he hacked it in two. All about him, Sons of Horus went toe to toe with the terrible creatures that had once been members of the 63rd Expedition.

Rotted hands clamped onto his armour from beneath the water and Loken felt himself being dragged down. He roared and reversed his grip on his sword, stabbing it straight down into leering skulls and rotted faces, but incredibly their strength was the greater and he could not resist their pull.

'Garvi!' shouted Vipus, hacking enemies from his path as he forged through the swamp towards him.

'Luc! Help me!' cried Vipus, grabbing onto Loken's outstretched arm. Loken gripped onto his friend's hand as he felt another set of hands grip him around his chest and haul backwards.

'Let go, you bastards!' roared Luc Sedirae, hauling with all his might.

Loken felt himself rising and kicked out as the swamp creatures finally released him. He scrambled back and clambered to his feet. Together, he, Luc and Nero fought with bludgeoning ferocity, although there was no shape to the battle now, if there ever had been. It was nothing more than butcher work, requiring no swordsmanship or finesse, just brute strength and a determination not to fall. Bizarrely, Loken thought of Lucius, the swordsman of the Emperor's Children Legion, and of how he would have hated this inelegant form of war.

Loken returned his attention to the battle and, with Luc Sedirae and Nero Vipus in the fight, he was able to gain some space and time to reorganise.

'Thanks, Luc, Nero. I owe you,' he said in a lull in the fighting. The Sons of Horus reloaded bolters and cleaned chunks of dead flesh from their swords. Sporadic bursts of gunfire still sounded from the swamp and strobing flashes lit the fog with firefly bursts. Off to their left Loken saw a burning pyre where the skiff had come down, its flames acting as a beacon in the midst of the obscuring fog.

'No problem, Garvi,' said Sedirae, and Loken knew that he was grinning beneath his helmet. 'You'll do the same for me before we're out of this shit-storm, I'll wager.'

'You're probably right, but let's hope not.'

'What's the plan, Garvi?' asked Vipus.

Loken held up his hand for silence as he attempted to make contact with his Mournival brothers and the Warmaster once more. Static and desperate cries filled the vox, terrified voices of army soldiers and the damned, gurgling voices that kept saying, 'Blessed be Nurghleth…' over and over.

Then a voice cut across every channel and Loken almost cried aloud in relief to hear it.

'All Sons of Horus, this is the Warmaster. Converge on this signal. Head for the flames!'

At the sound of the Warmaster's voice, fresh energy filled the tired limbs and hearts of the Astartes, and they moved off in good order towards the burning pillar of fire coming from the wrecked skiff they had seen earlier. Loken killed with a methodical precision, each shot felling an opponent. He began to feel that they finally had the measure of this grotesque enemy.

Whatever fell energy bestowed animation upon these diseased nightmares was clearly incapable of giving them much more than basic motor functions and an unremitting hostility.

Loken's armour was covered in deep gouges and he wished he knew how many men he had lost to the loathsome hunger of the dead things.

He vowed that this Nurghleth would pay dearly for each of their deaths.

She could barely breathe, her chest hiking as she drew in convulsive gulps of air from the respirator Maggard was pushing against her face. Petronella's eyes stung, tears of pain coursing down her cheeks as she tried to push herself into a sitting position.

All she remembered was a fury of noise and light, a metallic shriek and a bone jarring impart as the skiff crashed and broke into pieces. Blood filled her senses and she felt excruciating pain all down her left side. Flames leapt around her, and her vision blurred with the sting of the atmosphere and smoke.

'What happened?' she managed, her voice muffled through the respirator's mouthpiece.

Maggard didn't answer, but then she remembered that he couldn't and twisted her head around to gain a better appreciation of their current situation. Torn up bodies clothed in her livery littered the ground - the pilots and flight crew of her skiff - and there was a lot of blood covering the wreckage. Even through the respirator, she could smell the gore.

Cloying banks of leprous fog surrounded them, though the heat of the flames appeared to be clearing it in their immediate vicinity. Shambling shapes surrounded them and relief flooded her as she realised that they would soon be rescued.

Maggard spun, drawing his sword and pistol, and Petronella tried to shout at him that he must stand down, that these were their rescuers.

Then the first shape emerged from the smoke and she screamed as she saw its diseased flesh and the rotted innards hanging from its opened belly. Nor was it the worst of the approaching things. A cavalcade of cadavers with bloated, ruptured flesh and putrid, diseased bodies sloshed through the mud and wreckage towards them, clawed hands outstretched.

The green fire in their eyes spoke of monstrous appetites and Petronella felt a gut-wrenching terror greater than anything she had ever known.

Only Maggard stood between her and the walking, diseased corpses, and he was but one man. She had watched him train in the gymnasia of Kairos many times, but she had never seen him draw his weapons in anger.

Maggard's pistol barked and each shot blasted one of the shambling horrors from its feet, neat holes drilled in its forehead. He fired and fired until his pistol was empty, and then holstered it and drew a long, triangular bladed dagger.

As the horde approached, her bodyguard attacked.

He leapt, feet first, at the nearest corpse and a neck snapped beneath his boot heel. Maggard spun as he landed, his sword decapitating a pair of the monsters, and his dagger ripping the throat from another. His Kirlian rapier darted like a silver snake, its glowing edge stabbing and cutting with incredible speed. Whatever it touched dropped instantly to the muddy ground like a servitor with its dotrina wafer pulled.

His body was always in motion, leaping, twisting and dodging away from the clutching hands of his diseased attackers. There was no pattern to their assault, simply a mindless host of dead things seeking to envelop them. Maggard fought like nothing she had ever seen, his augmetic muscles bulging and flexing as he cut down his foes with quick, lethal strokes.