He glanced at the nervous faces around him, seeing the regimental insignia of Krieg, Logres and Erebus Defence Legion units. Every face was wrapped in snow goggles, scarves and helmets, but he could sense the fear in all of them.

'Place your trust in the Emperor,' shouted Uriel, 'He is both your shield and your weapon. Trust to His wisdom that there is purpose in everything, and you will prevail. Kill your enemies with His name on your lips and fight with the strength that He has given you. And if it is your fate to give your life in His name, rejoice that you have served His will.'

Uriel activated his power sword, coils of energy wreathing the blade in deadly energy.

'Let the aliens come,' he snarled. 'We will show them what it means to fight the soldiers of the Emperor.'

Chaplain Astador felt the pulse of the world through the ceramite plates of his armour, sensing the planet's pain at this invasion in every strand of life that took its sustenance from its spirit. The scent of his own burning blood filled his senses and allowed his ghost-self to commune with those who had gone before him, who had worn the holy suit of armour in ages past, whose perceptions of the universe were uncluttered by the fetters of mortal flesh.

He could feel the flaring energies of the soldiers around him, fear radiating hot and urgent, but also courage and determination. It was a potent combination, but Astador could not yet tell whether it would be enough to stand before these creatures that gave neither thought nor obeisance to the spirits of the dead and all that they could know.

Though he could sense individual intelligences lurking within the swarm, he could feel a single keening voice that lanced through the swarm, a single driving imperative that gave them great strength of purpose, but no will of their own. It felt like cold steel, a glacial spike driven through his ghost-self. The sheer horror of this utterly alien consciousness threatened to overwhelm Astador, and the awesome scale of such domination of the self beggared belief.

There was no hunger, no anger, no courage, or ambition in that imperative, only a single-minded desire to consume.

There was strength in that, to be sure, but also great weakness.

But should that cold steel imperative be broken, what then could such slave creatures achieve with no will of their own?

Casting his ghost-self further into the chill of the ghastly tyranid psyche, Astador probed for ways to do just that.

Captain Owen Morten hauled violently on the stick of his Fury interceptor, pulling a hard dive for the deck. Whiteness flashed past his canopy and he levelled his wings as he pulled out some forty metres above the ice. He feathered the engines, pulling around and craning his neck over his right shoulder. A trail of bright explosions bloomed in his wake, alien carcasses cartwheeling through the air and Morten's icy countenance hardened even further.

Hastily reconfigured to carry air-to-ground munitions following their landing on Tarsis Ultra, Captain Morten's squadron of Furies were taking the fight back to the tyranids. His last sight of the Kharloss Vincennes was of her launch bays in flames before the violence of the refinery's explosion had eclipsed her death throes. A blood price had to be paid for all their shipmates and the Angel squadrons were reaping it in the blood of these damned aliens.

Erin Harlen's Fury looped overhead, the bombs on his centre pylon pickling off in sequence to impact in a string of detonations that merged into one continuous roar.

Morten rolled his Fury, screaming back across the trenches below and checking that his two wingmen were still on station with him. High above, Lightning interceptors looped in lunatic acrobatics with packs of gargoyles, their pilots keeping the flying creatures busy while they delivered their explosive payloads. Even a cursory glance told him that the Lightnings would not be able to hold the flocks of aerial killers off their backs for much longer.

He thumbed the vox-link on his control column.

'We're going in again,' he said. 'Low altitude strafing run. Follow on my lead.'

'Captain,' warned Kiell Pelaur, his gunnery officer, 'we're all out of missiles. We don't have anything left to drop.'

'I know, lieutenant. Switching to guns.'

Morten pushed the nose of the aircraft towards the ground, the swarm rushing towards him through the canopy. The shuddering of the airframe increased and a red light flashed on the panel before him as the proximity alarms shrieked as the Fury's altitude dropped to a mere thirty metres. Flying at such height required the steadiest of hands on the stick, as the slightest error would smear the Fury across the ice.

But the commander of the Angel squadrons was amongst the best pilots the Kharloss Vincennes battlegroup could put in the air and his control was second only to that of Erin Harlen. The tyranids rushed towards them, plumes of ice crystals foaming in the wake of the screaming Furies.

Captain Morten pulled the trigger on his control column, sending lancing bolts of energy from the Fury's lascannon into the horde. Explosions of blood and ice tore through them as the powerful weapon fired again and again. Morten screamed as he fired, feeling the burning desire to kill every single one of these abominations in one fell swoop. He pictured a blooming red fireball, the destruction he could achieve by simply letting go of the Fury and allowing her a final, glorious death in the heat of battle.

Another red light began blinking as the last energy cell for the lascannon was ejected from the Fury's underside and the frequency of the proximity alarm rose to a shrill new height.

'Captain!' screamed Pelaur, 'Pull up! For the Emperor's sake pull up!'

Pelaur's shout snapped Morten from his visions of death and he took a deep breath, pulling back and hauling the Fury into a looping climb.

'Imperator, captain! That was some real close flying,' breathed Pelaur. 'That's the kind of thing I expect from Harlen.'

Captain Owen Morten didn't reply, picturing a giant valedictory explosion.

Pavel Leforto fired into the mass of aliens, terrified beyond thought at the scale of what he was seeing. Giant monsters lumbered through the charging mass of beasts, their snapping talons bigger than the claws on the lifting rigs that hauled girders in the smeltery.

The alien advance had faltered about ten metres from the trenches, the smooth ice coating the snow berm defeating their attempts to close the final gap. But already the smaller beasts were chopping into the ice to pull themselves closer. They died in droves, but following creatures used the corpses to push even closer. The advance had stalled, but it had granted the Imperial forces only the briefest of respites.

The noise of battle was tremendous: roaring guns, explosions, screaming and the inhuman rasping of the tyranids. A huge mushroom cloud erupted in the centre of the aliens as the Capitol Imperialis fired again, throwing ice and alien bodies hundreds of metres into the air.

The platoon briefings told him to shoot at the larger tyranid creatures, the sergeants claiming that this would disrupt the smaller beasts. Quite how that would work was a mystery to him, but he had spent his entire adult life obeying orders and wasn't about to stop now.

He ejected a spent power cell and slotted home a fresh one with trembling hands. Raising the rifle to his shoulder, he sighted along the barrel at a towering monster with a flaring bone crest rising from the back of its skull. Powerful, clawed arms held a long gristly tube that dripped slime, and surrounding the monster were dome-skulled creatures with bony protuberances growing from their upper limbs. He aimed a shot at the largest creature's skull, his bolt ricocheting from the thick fringe of bone. A missile streaked from behind him towards the giant monster, exploding against the bony growths of one its chitinous protectors.