Concealed by the night's darkness, the lictor slid through the darkness of the city, making its way towards where the pheromone signature of its alien kin was strongest.

Drawn towards the valley mouth, the lictor moved with stealth and speed, like a flickering shadow that darted from cover to cover, unseen and unheard, even by those it killed. On occasion it had encountered prey and killed them to bolster its energy reserves before moving onwards.

The lictor rounded the corner of a ruined building, feeling the scene before it wash through its sensory receptors in a heartbeat. It sensed heat, dead kin and a pheromone signature that surely indicated a leader beast of prey.

Captain Bannon's eyes scanned from side to side as Inquisitor Kryptman and Locard performed their grisly autopsies on the tyranid corpses they had been ordered to gather. For what purpose, Bannon didn't know and didn't care, so long as it helped the defenders exterminate these xenos. He and his men had travelled the length and breadth of the city's armed forces, instructing every squad in the best methods of combating tyranids, pointing out weak spots in their natural armour, vulnerable organs and the correct hymnals to recite both prior to and following combat.

It was slow work, but it was paying off, as the daily casualty rosters, while still horrifying, were not as high as they might have been. Bannon understood that this could partly be accounted for by the weakest men having already fallen and the strongest remaining, but the men of Erebus had learned quickly and he knew that alien losses were much higher.

He had been impressed by the Ultramarines and the Mortifactors, though he found it hard to believe that both were descended from the same gene stock. His proud lineage came from the blessed Rogal Dorn and he briefly wondered how many of the successor Chapters of me Imperial Fists had deviated from their original teachings. Not many, he surmised, if the Black Templars were anything to go by.

'Captain Bannon,' said Inquisitor Kryptman.

'My lord?'

'There is nothing here of value. Burn it all.'

Bannon said, 'Aye,' and nodded to Brother Elwaine, originally of the Salamanders Chapter, who raised his flamer and sent a sheet of burning promethium over the mound of cadavers. His mouth twitched in a smile of satisfaction as he watched them immolate.

'Brother-captain,' snarled Henghast of the Space Wolves. 'Enemy near!'

Bannon knew better than to doubt the Space Wolfs senses, but before he could do more than face outwards, it was upon them.

One of the inquisitor's Storm Troopers was lifted from the ground, multiple barbs bursting from his back in a spray of blood and bone. Hellguns fired blindly into the dark, the soldiers having lost their night vision looking into the fire. Another soldier fell, his legs shorn from his body by a massive swipe of chitinous claws.

He saw it in the flickering glow of the flames. A lictor, its upper claws unsheathed and bloody. He raised his bolter, aiming for the junction of thorax and legs, and fired a hail of shells. The lictor spun away from his shots, speeding around the edge of the burning pyre of alien corpses.

Bannon ran around the fire, shouting, 'Henghast, go left! Elwaine, cover!'

Elwaine widened his stance, bracing his flamer as Henghast made his way around the other side. Kryptman had his pistol drawn and Locard twisted his head left and right, chattering excitedly to the inquisitor.

He scanned the ground before him, shutting out the screams of those wounded by the lictor. Damn, but it was quick. Where had it come from?

Bannon heard it a second before it attacked.

Powerful muscles hurled the lictor straight over the pyre, its claws aimed at his heart. He dropped, rolling and firing in one motion. Its claws ploughed the rockcrete, shearing through his shoulder guard and drawing blood. His shots went wild as a tongue of flame washed over the lictor.

But it was no longer there, vaulting from Elwaine's line of fire and smashing the Space Marine from his feet. Clawed hands ripped the flamer from his grip and tore his arms from his sockets in a flood of crimson. Elwaine dropped with a grunt of pain, still kicking at beast as it dismembered him.

Bannon fired again, this time drawing a screech of pain from the lictor as his bolts penetrated its chitinous hide. It spun, blindingly quick, and barbed tendons lashed out, skewering his bolter. The weapon exploded as the propellant in the ruptured shells ignited and Bannon fell back, his gauntlets melted in the blast.

Hellgun fire slashed at the lictor and over the screams Bannon head Kryptman's voice.

'Don't kill it! For the Emperor's sake, don't kill it!'

He rolled to his feet as the lictor came at him. drawing his combat knife and leaping to meet it.

As he leapt he realised that the lictor wasn't coming for him.

It was going for Inquisitor Kryptman.

Kryptman fired his pistol at point blank range, blasting clear a portion of the lictor's upper thigh. It stumbled, but its mantis-like upper claws swept down to eviscerate the inquisitor.

Then Henghast was there, his power sword sweeping down to intercept the blow. The former Space Wolf spun low and slashed his blade through the lictor's upper claws, drawing twin spurts of black blood. It roared in alien rage and once again its barbed hooks lashed out, entangling the Space Marine's sword arm. Its lower arms punched out, ripping through Henghast's armour and hurling him through the air. Blood pumped from its severed claws as Bannon fought to draw his own sword with his scorched hands. His power armour dispensed pain retardant drags into his system.

The lictor spun away from the fire, its wounds driving it from the fight before he could reach it. He stumbled towards the inquisitor and Locard. Both were alive. Shaken, but alive.

'Get it, Bannon!' hissed Kryptman, 'but for the love of the Emperor, don't kill it. We need it alive!'

He stumbled after the monster as it sped towards the city walls, shouting into the vox, 'Uriel, Astador, anyone! I need help. I am in pursuit of a lictor heading north-westwards to the walls. Close on my position, and if you see it subdue it. I repeat, subdue it, do not kill it!'

Uriel, Pasanius and ten warriors from the Fourth company ran from the walls towards the source of Bannon's desperate call for aid. Leading his men in prayer, he had been amazed at the last portion of Bannon's message. A lictor on the loose and they were not to kill it?

'Spread out,' ordered Uriel.

'Why in the name of all that's holy can't we kill the damned thing?' said Pasanius.

'I don't know, but Bannon must have a good reason.'

'How are we supposed to see it, I thought these things were chameleons?'

'Just follow the screams,' said Uriel as he heard cries of pain a hundred metres or so to his left. His armour's auto-senses penetrated the darkness with ease and he saw the shimmering outline of the creature as it butchered its way through the picket line of squads protecting the army's rear.

'With me, now!' shouted Uriel and took off towards the lictor. He opened a channel to Bannon. 'I see it, it's in north sector delta!'

Whether the monster needed to kill or simply took pleasure in the act, Uriel didn't know, but it had stopped to slaughter the men stationed there. Uriel raised his gun, his finger tightening on the trigger before he remembered he was not to kill the creature. It spun away from him and leapt for the side of the rock face, its lashing hooks digging into the rock and hauling it rapidly upwards.

'It's getting away!' shouted Pasanius.

'Not if I can help it,' snarled Uriel, switching his bolter's shot selector to single shell. The lictor scaled the mountainside in jerky leaps, several of its fleshy grapnels hanging useless at its side.