He had tasked them with targeting sinners — the iniquitous, the mercenary, the impure — and they had made their solemn way into the hive, dispersing like a cloud of flies along elevator shafts and unknown duct crawls, to do that very thing. The hivers were fools if they thought the Cuspseal floor-rents were the only way up from the underhive, and the refugees had scattered across the city in defiance of the their so-called ''containment''. From the lowest to the highest tiers, in every shadowed recess and crowded street: a cry, a shout, the wet retort of metal finding flesh, and then only pumping blood and sprinting feet.

Had each and every victim been a sinner? Was every last head the fitting trophy of a slain delinquent who deserved his fate? No.

Of course not — no more so than any being may be considered guilty for the raft of petty evils for which, every day, every human was accountable. Here were the heads of the innocent mixed with the stolen skulls of scum, but he'd wager that each murderer would now convince his or herself, for the sake of their conscience, that their victim had been an abomination worthy of execution. That their brutality had been undertaken in the name of the Emperor. That no matter what violence they had committed, what horror they had seen, it was all excusable as part of their new lord's Holy Campaign.

Sahaal owned them all, now. Truly, the human mind was a wonderful thing.

But more important still, in the act of chaining themselves to his will, this horde of vigilantes, these thousand-strong killers, had injured the hive more than he could ever hope to have achieved alone.

The number of lives taken was irrelevant. Alongside the city's millions this mountain of skulls was a tawdry fraction, and yet... and yet in every level, in every township and city, the fear would be felt. He knew it, as a cognitor knows numbers and a poet knows words.

Let the Civilian Worship Channel deny it. Let the Preafects shake their heads and ring their bells, and claim that all is well. The more it was refuted, the more the rumours would spread. A wave of murders — insidious, motiveless, random. A slinking tide of death.

In a single disparate swoop, more punishing than any spectacle, more invidious than any gaudy massacre that could claim a million lives, fear would blossom on a tsunami of rumour and suspicion. He could well imagine the whispers, the frightened glances, the questions raised in every home.

Who is responsible? What do they want?

What had the victims done to incur such wrath?

The hive would become a restrained place. Doors would lock. Neighbours would cast troubled glances across cramped habways and avoid conversation. Families would huddle in the dark and whisper of ghouls in the night.

Kill a thousand men and they will hate you.

His master's voice, slipping upon runnels of ghostly memory.

Kill a million men and they will queue to face you. But kill a single man and they will see monsters and devils in every shadow. Kill a dozen men and they will scream and wail in the night, and they shall feel not hatred, but fear.

Sahaal nodded, pleased.

He had taken the first step. His brothers were coming for him, and he would be damned for a weakling and a fool if he was unready.

'Summon the captains,' he said to Chianni — and for an instant he fancied that he was back upon Tsagualsa, commanding his raptors, directing the Night Lords with the focus they required.

'Of course, my lord,' Chianni trilled, shattering the illusion. 'In respect of what?'

Sahaal grunted, eyeing the skulls with half a smile.

'In respect of war, condemnitor. What else?'

Another moment's introspection, as he paused for his warriors to gather, another slip back in time: once more to the great halls of the Vastitas Victris and the Night Lords fleet, once more to the side of his master, black-feathered and veiled, leaning upon the Vulture Lectern to address the brothers. Such reminiscing gripped Sahaal more and more often, and at times the vividity of the visions scared him — so convincing was their colour, so remarkable their detail. At times he feared he was going mad.

But always he relished the opportunity to revisit his master's lifetime, and with each occurrence he immersed himself further in the words, treating each as a message intended for him alone. His master's legacy lay with him now. He must be true to the primarch's teachings.

'To kill an enemy, strike you in three places.'

That was how the lecture began, initiates and veterans side by side — Marine and Raptor and Scout and Terminator — each an equal in their lord's eyes, each dwelling upon every word with fevered concentration.

'Strike you at his hands, and he shall not cut you.'

'Strike you at his heart, and his life shall wane.'

'Strike you at his mind, and his courage shall fail, his faith shall leave him, his defeat is assured.'

Sahaal's enemy was the hive. He gave thanks to his master's ghost and, when finally his captains scurried to join him, he sent six squads to remove the city's fingers, one by one.

Surface to air batteries. Orbital defences. Overwhelmed by sudden coordinated attacks, sabotaged beyond the point of rapid reconstruction. Strike you at his hands, and he shall not cut you.

Four groups he sent outwards into the edges of the underhive, where the pulsing hearts of the city stood and rumbled.

Power stations. Geothermal vents. Great melta charges and jury-rigged bombs tightened against churning pumps, depriving the hive of its power and heat. Strike you at his heart, and his life shall wane.

And the mind... The onslaught upon the city's mind, he led himself.

He had expected militiamen, or perhaps PDF regiments, skulking and morose in the xanthic lights at the compound's entrance, passing bacsticks and hipflasks to fend off the cold. As it was, he was not alone in acknowledging the supreme importance of propaganda, and it would not be so easy to gain entry. Clearly he had underestimated the vindictors' commander.

The city's population was jumpy — the murders had seen to that — and with citizens locking themselves away in their habs, mumbling prayers to keep the monsters away from their doors, Sahaal's small war-band had little trouble reaching its destination undiscovered: sneaking through secret streets, forgotten shafts, desolate tramways. At the midtier intersection his scouts had indicated, they pulled themselves from a disused duct and prowled towards the industrial arcade that was their destination, only to find no fewer than six Preafects ringing its heavy gates.

Glutted by the success of their stealth, Sahaal cursed himself for not anticipating that their goal would be better guarded. The Shadowkin melted into the adjacent alleyways, awaiting his command. He sized-up the enemy with a practiced eye.

Two dervishi, heavy carapace armour marked with red stripes, hefted actuator-stabilised lascannons at either edge, with a quartet of shotguns — no less dangerous for their lighter armament — prowling between. In the wake of the attack upon the starport, clearly, the Preafects were taking no chances.

Sahaal grinned despite himself. He had spent too long on his throne, too long brooding and sulking in the gloom, to be dispirited by the odds. It felt good to be active again.

He took them from above, ululating as he dropped into their midst. The first dervishi he had cleaved apart before the squad was even aware of his presence, and before they could gather their instincts and round their weapons he'd stepped through the bloodspray to find a second victim, punching claws through glossy visor and skull alike, twisting through meat and bone. A shotgun pulsed to his left, a panicky blast that barely scratched him, and even as he dislodged the shattered face from his claws he was raising his bolter with his free hand, planting a round in the assailant's face and ducking beneath his thrashing grasp like a ghost, a blue and bronze streak, too fast to follow. By the time the shell detonated in the muffled confines of the dead man's helmet, far behind him, Sahaal had closed with the remaining men. The hiss of a charging lascannon pricked at his senses and he bounded across the shotgunners with a precise burst of his jump pack — snatching at their heads with his talons and dragging them behind him, flinging them with a final shriek — diced by the blades that released them — at the remaining dervishi. The lascannon discharged into their tumbling bodies and vaporised itself — and much of its wielder — in an orb of incandescence, scattering ash and fluid.