No matter what happened, Uriel vowed that he would do what he could for Serj Casuaban. The man might be guilty, but it was clear that he at least felt some remorse for what he had allowed to happen.
At each junction of corridors, the medicae would point and then set off once more, alert for any sign of the Unfleshed or any other enemy.
Though he saw no threats, Uriel could sense a fearsome potential building, as though a great power was even now gathering its strength. He cursed his vivid imagination and shook off such morbid thoughts as Leodegarius halted.
They had come to a junction with two passages stretching off into the darkness, left and right, while a wide set of iron stairs led up into sputtering, fitful light. Frozen stalactites of ice hung from the brass balustrade.
'Which way, medicae?' demanded Leodegarius.
'Up, we need to go up.'
When the attack came, it was with a precision that caught everyone by surprise.
The warriors on the right flank came under attack first; a beast with a hunched spine and long arms wrapped in muscles like steel hawsers tore the head from the warrior on point and hurled it back at his comrades.
A creature with a fused exoskeleton like armour barrelled into the warriors on the left, scattering them and crushing two warriors to death with the sheer force and mass of its charge.
As they reached a ramp that led further upwards, Uriel saw a great shadow detach itself from an alcove in the wall ahead, its body pulsing with light as it came at them. This creature was a hybrid of two forms fused into one, a union of flesh that could not possibly be alive, yet had somehow found a way to exist.
Uriel saw the creature's internal twin oozing beneath its newly formed skin, a howling face pressed against its pallid sheath of flesh. Its muscles seethed with light and its fist caved in the helmet of the Grey Knight nearest Uriel in one quick motion.
Blood squirted from the headless corpse and the silence of the House of Providence was brutally ended.
The Grey Knights reacted with all the speed and ferocity that Uriel expected. No sooner had the beast appeared in their midst than every halberd was swinging for it. Storm bolters opened up in a coordinated volley of fire. Blazing light and deafening noise filled the space and sprays of light and flesh flew from the Unfleshed as it shuddered under the impacts.
A fist with the mass and force of a lump hammer swung out and smashed the breastplate of a Grey Knight, exiting from the warrior's back in an explosion of blood and ceramite. Uriel ducked the return stroke and opened fire, the bark of his weapon adding to the din.
Serj Casuaban dropped to his knees, his arms pulled in tight as Pasanius stood over him.
Too close to use his psycannon, Leodegarius thrust with his polearm, the glowing blade hammering into the back of the creature. It roared in pain, the shimmering, fiery tip of the blade erupting from its swollen chest. The creature tried to spin around to face its attacker, but Leodegarius's strength and mass was too great and he held it fast.
'Hurry!' shouted Leodegarius. 'Kill it!'
The two surviving Grey Knights moved in, firing as they went, and Uriel was struck by their utter fearlessness in facing this terrifying creature. More bloody craters were gouged in its flesh by a host of mass-reactive shells, yet it appeared not to feel them.
Leodegarius dragged the beast to its knees with a heaving twist of his polearm and Uriel ran to join the Grey Knights, his sword leaping to his hand. Their blades stabbed the creature and its roars of pain echoed from the walls, shaking icicles from the ceiling.
The creature's oozing twin erupted from the Unfleshed's chest in a monstrous parody of birth, its vile, putrescent form slathered in blood and its grasping claws reaching for the nearest warrior. Its claws were sheathed in light and they parted the Grey Knight's armour and flesh as if they were wet paper. The parasitic twin tore through the muscle and bone of the warrior's chest, sundering his heart and ripping the mass of his internal organs to bloody ruin.
The Grey Knight dropped to the ground, breaking the neck of his killer as he fell.
The Unfleshed was weakening and Leodegarius was finally able to bring his psycannon to bear, unleashing a hail of psychically impregnated bolts into the beast.
The effect was instantaneous, and the creature toppled over, a ruined mass of shredded flesh that could not have endured such horrible damage without the power of the dead to sustain it.
Uriel felt no glory at the kill, only regret, but he did not have time to wallow in it.
Fresh foes were upon them.
They came in scads of light from the wards all around them, their shrieking howls of pain screeching along Uriel's nerves. Looking deeper into the light, he saw a host of horrific figures sweeping towards them as though driven by some powerful wind.
They were diseased figures, crippled figures, gaunt, emaciated and burnt forms in billowing surgical gowns: amputees, men with no eyes and women with hideous scars all over their bodies. Every hand was extended as though pleading for alms, and those with eyes were haunted with the angry memory of pain and suffering. A bow wave of frost cracked the walls before them, crazed patterns spreading in waves of white.
'What in the name of the Emperor are they?' screamed Casuaban when he looked up.
'Phantoms,' said Leodegarius, 'the tormented nightmares of the wounded you care for. The power of the warp is getting stronger and they are becoming real.'
'I take it they are dangerous?' said Uriel, raising his sword.
'Lethal,' said Leodegarius. 'Do not let them touch you. They will feed on your life to ease their suffering. Medicae! Which way?'
Casuaban looked around, as though his surroundings were suddenly unfamiliar to him.
'Quickly, man!' shouted Leodegarius.
'Up! Up another level!'
Leodegarius turned away from them and stood in the centre of the corridor directly in the path of the seething horde of nightmares. 'Cheiron, with me! Uriel, get behind us!' he cried. 'Onto the ramp!'
'What are you going to do?' cried Uriel.
'We're going to stop them,' said Leodegarius.
Uriel backed away from the Grey Knights as he tasted the actinic tang of psychic energy and his sword sparked and fizzed in the presence of such power. Hurriedly, he gathered Pasanius and Casuaban and backed onto the ramp that led up to who knew what.
Gunfire roared from the Grey Knights' weapons, Cheiron's bolts appearing to have little effect, but those of Leodegarius tearing through the figures like fire through cloth. As the ghostly nightmares drew ever closer, however, Uriel saw it wouldn't be enough.
'I have to help them!' cried Uriel.
'Wait!' shouted Pasanius, pointing towards the two Grey Knights.
Uriel looked over his shoulder and watched the silver-armoured warriors seem to swell as crackling arcs of lightning flared from the leading edges of their armour.
Both warriors held their polearms upright and their free hands were extended as they chanted the same mantra. 'Foul conjurations of the warp, we know thee. Unclean power from beyond the veil we abhor thee. Fell daemons of the Empyrean we defy thee.'
Leodegarius slammed his polearm onto the metal deck. 'Thrice cursed you are and thrice damned be thee.'
Serj Casuaban cried out and Uriel felt the rush of power as an enormous white fireball exploded into life around the Grey Knights. Wreathed in the flames, Leodegarius and Cheiron shone like angels of the Emperor, the roaring power contained around them by sheer force of will.
'Spawn of evil I cast you from this place!' cried Leodegarius and the blazing white fireball filled the corridor. Billowing flames exploded outwards from the Grey Knights, and the screams of the ghostly figures were swallowed in the seething roar of the fire.