The visible portion of the Heretic Astartes’ face was bloated and pallid, the face of a man close to death, but a fevered mirth lit up his eye. Scabbed lips quivered with an avuncular chortle. He held up a clubbed hand whose little finger was a limp tentacle. A greening nail pointed directly at Varens.

‘You first!’ he said.

The Plague Marine raised a bolter flaking with rust. Such a thing should not have functioned, but the servants of Chaos were not bound by natural law.

The heretic roared with laughter as the gun slammed out bolt-rounds. Varens threw himself aside as men were cut down all around him. Mass-reactive shells pierced flesh and detonated, tearing men into red scraps that were quickly lost to the mud.

‘I said you first!’ Mumbling annoyance, the Plague Marine stomped forwards, crushing the rib cage of a wounded auxiliary. Red-tinged water filled his bootprints.

The thing was monstrous, a blasphemy against mankind and his proper place in the universe, and it was unstoppable. Lasbeams pattered off its armoured hide. Expanses of exposed, leathery skin hissed as they burned. The Plague Marine acted as if nothing were amiss.

‘Father Nurgle waits for you in his garden, little man,’ he said as he racked a final bolt into his gun and levelled it at Varens. ‘Be glad, you go to a better place than this. When your joy has subsided at the sight of your new home, be sure to tell him Odricus of the Death Guard’s fifth sept sent you.’

From nowhere, Bolus appeared, ducking in under the Plague Marine’s arm. The traitor moved to react, but its only weakness, or so it seemed, was that it was as slow as the dead it shepherded. Bolus was not.

With a move that would have impressed the commandos of the Militarum Tempestus, he jammed his gun up and under the Heretic Astartes’ helm. The creature growled as the weapon forced the helm’s metal away from the conjoined flesh.

‘So you can be hurt,’ said Bolus. ‘Good.’

He pulled the trigger as the traitor wrapped its diseased hand around his throat.

Devised by the high sciences of the Emperor to withstand great damage, and made more resilient yet by the magics of Chaos, the Plague Marines of Nurgle were nigh on immune to harm. But they were not unkillable. Even they suffered from a point-blank lasgun shot to the face.

The traitor’s head cracked open with a wet squelch. Curls of atomised flesh rose from its helmet. In the ruins of its throat came a last, bubbling breath, and then it toppled forwards, knocking Bolus back into the mud and landing squarely on top of him.

Bolus was buried by his dead foe; only his arm protruded from under the traitor’s cracked battleplate.

Varens threw himself forwards and dug into the mud. Bolus’ hand twitched and scrabbled. ‘Hang on, Bolus! Hang on, my friend!’