‘It is worse than that,’ said Heka’tan, in a voice that sounded only partially like his own.

Rather than being shocked, Arcadese dropped his shoulder for the attack he knew was coming. He turned, bringing up another flash-sabre, parrying Heka’tan’s bone-blade that had rapidly morphed from his fingertips.

‘How did you know?’ asked the assassin.

Their blades were locked, spitting sparks and bone chips.

‘The smell,’ Arcadese told his attacker. He smiled as a thunderous bulk rammed into the assassin, crumpling his flank.

‘I reek of ash and heat,’ said the real Heka’tan, having exploded from the shadows where he’d been lurking since his initial departure. ‘Your wound obviously wasn’t quite deep enough.’

They wrestled, Salamander and assassin, the latter transforming even as they moved.

A metamorphic catalogue of identities blended and re-blended across the alien’s face, first the landman, then the subtle facial shift to the marshal, finally the Custodian upon which it settled.

‘You are no lion,’ snarled Heka’tan, snapping a vertebra in the creature’s spine.

Around them, the crowd shrieked and shouted in terror. The throng pressing up against the door became a crush.

The assassin mewled in pain, a tonal, bird-like resonance that set the Salamander’s teeth on edge.

‘Clever,’ it hissed through clenched teeth, bringing its knees up sharply into Heka’tan’s sternum and vaulting him off its body.

The Salamander landed in a wide sprawl, a few metres away.

‘A lie to snare a liar.’ Arcadese came crashing in, two-handed, with the flash-sabre. A ball of light blazed and faded at once as the weapon connected with stone not flesh.

The assassin bounded backwards, weaving to avoid the Salamander’s heavy cross as it came within range.

The bone-blade became a Custodian’s training spatha in its right hand and it slashed at Arcadese.

Faux-steel screeched against true-steel as the Ultramarine took the blow on his bionic arm. It was only his forearm that was augmetic but it provided an effective foil. He stomped, aiming for the assassin’s foot to cripple it. Rockcrete splintered beneath him, the ground webbing outwards in tiny fault lines.

‘Yield, you are undone,’ snapped Arcadese.

Heka’tan loomed in snatches of the Ultramarine’s vision, just behind the assassin.

He flung his arms out and snapped them together like mechanical foundry tongs, seizing the assassin in an onyx-black grip.

‘You are the ones who are undone,’ the creature cackled, spitting a gobbet of intestinal acid that seared Heka’tan’s cheek. The Salamander didn’t even flinch, he merely squeezed.

Arcadese caved in the creature’s face with a bionic fist, the bone-blade ripped from the assassin’s grasp but still lodged in his forearm.

It wheezed like a perforated lung as Heka’tan slowly crushed it. The integrity of the creature’s mimicry was breaking down with the onset of its death. Personas strange and familiar raced across its form and countenance like the changing of the seasons.

‘What was your purpose here?’ Heka’tan growled, bearing the lacrymole down, for it could be no other xenos abomination. ‘What greater evil are you masking?’

Vampiric shapeshifters, the Emperor and his Legions had taken great pains to ensure the annihilation of the lacrymole and yet, like the Terran atom-roach, they refused to become extinct.

Even its true form was nebulous, a conglomeration of wrongly shaped limbs and distended flesh-parts. Its eyes were discernable, however – pitiless black pinpricks of endless hate.

It died laughing, a hot, wet sound more choke than mirth.

‘What I cannot fathom,’ uttered Heka’tan when it was done and the broken sack of muscle and bone shards slid from his forge-smith’s grasp, ‘is how it could emulate a Custodian?’

Arcadese mashed the lacrymole’s quivering cranium with his boot. The bionic force he applied was enough to pulp it. The lacrymole needed to tastetheir prey, absorb them, before they could copy them biologically. To emulate one almost perfectly, it meant this alien had somehow bested and consumed the biological matter of one of the Emperor’s lions. Such a thing didn’t seem possible.

The Ultramarine shook his head. ‘What did it mean, “You are the ones that are undone”?’

Planetkill

I

THE ANSWER CAME with the thunderous boom that shook the flagstones of the auditorium floor. The explosion emanated from far beneath them, in the lowest levels at Cullis’s nuclear hub.

Subdued by the death of the assassin and the relief that brought, the trapped Bastionites started to panic anew and hammered at the door again.

Another explosion rocked the chamber and a crack formed underfoot. A clutch of senators disappeared into the darkness and in the plume of fire that spewed up after them.

One of the clave-nobles had broken free of his bodyguards and was tugging at Arcadese’s robes. ‘Save us… please.’

The Ultramarine looked down on the man with disdain.

Heka’tan interrupted his response. ‘We have been doubly deceived, brother.’

A twitch below Arcadese’s right eye betrayed the pain of the injuries the Ultramarine had sustained in the fight with the lacrymole assassin. He was angry at being duped. ‘A saboteur?’

‘Willing to destroy an entire planet to keep its secrets,’ said Heka’tan. Another tremor shook the chamber. A column split from its dais and crushed more of the civilians. There would be no hope of restoring order now.

‘Then these minor explosions are merely a preamble to something much bigger.’ The clave-noble was still scrabbling at the Ultramarine’s garb. He pushed the human away. ‘Begone! By holding court with Horus you have doomed yourself and your world.’

‘Perhaps not…’ Heka’tan was looking past the frightened crowd to the door. The broken masonry had fallen against it. The column had been heavy enough to put a wide crack in the door’s surface.

Some of the trapped civilians were even now pulling at it.

‘Stand aside,’ Arcadese bellowed, ‘in the name of the Legiones Astartes!’

The frightened throng parted for the two warriors who reached the door and each taking a side of the fissure, which was deep enough to get their fingers in, pulled. The stone door came away in chunks now that its structural integrity had been compromised. The crack widened.

Bullied to the front by his entourage, Vorkellen was right behind the Legionaries.

‘Get us out,’ he pleaded in a small voice, clinging to Heka’tan’s arm. ‘I too have been deceived.’

The Salamander looked down at him like he was the intestinal remains of an enemy he’d just gutted. ‘Where is your ship?’ he demanded, before the majority of the auditorium floor collapsed into a fiery chasm. Most of the senators went with it. Only those clustered next to the exit were spared death by fire.

‘Close, at the end of the gangway just outside,’ said the iterator. All of his suave self-assurance was evaporating before the prospect of his imminent demise.

Debris was falling from the ceiling, killing Bastionites by the score.

The gap in the door was wide enough for the Legionaries to squeeze out, which meant it was also large enough for the humans too. There were precious few left, just the clave-nobles and a handful of senators and marshals, and the iterator with his cronies of course.

Arcadese was first out and began waving the others on. Heka’tan was last through just as an almighty conflagration swept across the sundered auditorium. Smudged silhouettes in the smoke cloud screamed for rescue but the Salamander closed his senses to them.

‘They’re good as dead,’ he said as he met the hard gaze of the Ultramarine. It wasn’t an easy choice to make.