'The old fashioned way,' he breathed. 'Straight through them, eh? Pasanius, Henghast and I will hold them, you get to the queen!'

Uriel nodded and the four Space Marines raced towards the guardian beasts.

Pelantar saw what they intended and fired a carefully aimed blast towards the tyranids. Two reeled from the fusillade, their carapaces no match for the blessed ammunition of the Deathwatch.

But in doing so, he neglected his own defence for a fraction of a second.

And that was all his foes needed.

With a snap of claws, the heavy bolter was smashed apart and Pelantar was lifted from his feet in a massive set of powerful talons. He fought with every last bit of strength, punching bloody holes in the beast's carapace, but it was too late. With a bellowing roar, the beast ripped Pelantar in two, tossing the shorn halves away for the scavenger beasts to feed on.

Damias and Pasanius attacked while the beasts Pelantar had given his life to wound still staggered from his shells. One burned in the flames as Damias punched through the other's carapace with the lethal energies of his power fist. Henghast joined Pasanius in attacking the burning monster.

Uriel ran for the bloated belly of the Norn Queen, his sword raised to strike down the final beast between him and his goal. Its claws snapped shut and Uriel swept his sword through them. He leapt to meet the creature, ducking inside its guard as it flailed its razored claws at him, slashing its own flesh to ruin.

Uriel pulled himself up the creature's body, its bony exo-skeleton providing ready-made handholds. The creature thrashed as it sought to dislodge him, hacking itself bloody as its claws tried to pluck him from its body. Secondary jaws punched down through his breastplate, biting a fist-sized chunk of flesh from his chest and tearing free a portion of his pectoral muscle.

Uriel roared in pain, but kept his grip on the beast's ribs. He pulled himself to the armoured plates of its shoulders and drove his sword into its neck. Black blood spurted and the beast screeched in agony as it died. The monster's death spasm wrenched the sword from his grip.

Before it collapsed, Uriel vaulted from its shoulders onto the glistening walls of the chamber, his fingers closing on the hardened flesh of the Norn Queen's hide. Hordes of me scavenger organisms closed on him as he climbed, biting and clawing him. They clambered all over him, even squeezing inside his armour, their weight alone threatening to prise him loose.

Despite the pain-suppressors, his chest was bathed in agony. He batted clear the scavengers long enough to draw Kryptman's pistol and press it against the belly of the Norn Queen.

Feeling his grip on the queen's flesh sliding free, he pulled the trigger.

He felt a blast of unimaginable heat as the hrud mechanism activated, lancing a column of fire, hotter that the heart of a star, through the thick flesh of the Norn Queen. A fraction of a second later the pistol bucked in his hand as the shell containing the gene-poison fired into its body.

He dropped the pistol and felt himself sailing through the air as he finally lost his grip on the queen's hide. Uriel twisted as he fell, splashing into the slimy floor of the chamber. He screamed in pain as noxious fluids spilled into the wound on his chest.

He rolled, crushing the scavengers beneath his weight and weakly tried to rise to his feet. He saw Damias destroy the creature he fought with repeated blows of his power fist. Pasanius was hauled from his feet by his blazing foe and lifted high above the ground. Henghast hacked at the beast's legs, but it refused to die.

The beast's claws crushed Pasanius's silvered arm, the metal buckling under the creature's incredible strength. Uriel reached for his sword, before realising it was still embedded in the tyranid warrior creature.

He looked up at the hissing shape of the Norn Queen's head and felt a terrible despair flood through him.

The gene-poison had had no effect on the monster.

They had failed.

Trask lifted the backpack, its contents spilling from the tears like glittering, precious rain. His ugly swollen features were twisted in hate and anger.

He kicked Snowdog in the ribs and again in the face.

'You stupid bastard,' he snarled. 'Did you really think I was gonna take all the crap you kept shovelling me? Two years I gave you and this is all I get?'

Snowdog looked up through a mist of tears and his own swelling features. Over Trask's ranting he could hear the door several floors below finally give in to the inevitable. He pressed his back to the wall in an attempt to push himself to his feet. Trask kicked out at him again, but Snowdog rolled aside and Trask's boot smashed into the stone of the wall.

He howled in pain, but recovered before Snowdog could do much more than slide over on his side beside the supine Jonny. The big man was still alive, saw Snowdog. Bleeding badly, but still alive.

Not for much longer if he couldn't deal with Trask.

Hideous screeching filled the stairs below, and he could imagine the aliens scrambling over one another as they leapt and bounded towards the upper levels. He fumbled around beneath Jonny's body, smiling to himself as he felt metal and wood in his grip.

He twisted his head to look at Trask.

And suddenly it all made sense. The swelling on Trask's face wept a purple pus and Snowdog knew that the lone creature that had attacked the column of refugees must have sprayed Trask with some kind of scent that drew these aliens to him like flies to shit.

He smiled at the aptness of the phrase.

'What the hell you smiling at?' said Trask, reaching for fresh shotgun shells.

'You, man. It's been you they've wanted all along.'

'Huh?' said Trask as Snowdog rolled to face him, Jonny's hunting rifle held out before him.

'You want him?' he yelled to the aliens below. 'Well, here he is!'

Snowdog fired the huge rifle, feeling the monstrous recoil crack yet another rib. The impact hurled Trask back down the stairs, a huge portion of his torso simply blasted away by the shell. He crashed down onto the landing below, his body a mangled mess. Tyranid beasts swarmed over the landing, but halted at Trask's body, hacking and slashing it to shreds.

While the scent of whatever was on Trask was keeping the aliens busy, Snowdog used the rifle as a crutch and painfully got himself to his feet. Briefly he considered trying to lift Jonny, but quickly dismissed the idea as insane.

He heard more footsteps above him and laughed in relief as Tigerlily and Lex sprinted downstairs.

'What the hell's going on?' yelled Tigerlily.

'Later,' said Snowdog as he fought through the pain and climbed the stairs. Between them, Tigerlily and Lex managed to lift Jonny and the battered foursome limped up the final set of stairs to the top level of the medicae building.

Snowdog had never been so glad to reach somewhere in all his life.

'Where's Silver?' he said.

'She's safe,' said Tigerlily, pulling him onwards. 'Come on, the entrance to the caves isn't far. Let's get the hell out of here.'

'Best idea I've heard all day,' said Snowdog.

Less than twenty Space Marines remained. Heroism the likes of which Learchus had only read about in history had kept them alive for nearly forty minutes, but the end was drawing near. Horrified men of the Guard watched the Space Marines' last stand from the District Sextus wall, unable to help them. Learchus would not have wanted their help anyway.

This was a glorious battle, a fitting way for any servant of the Emperor to meet his end. He and Chaplain Astador fought back-to-back, killing aliens with ferocity and skill.

A mound of alien corpses surrounded the Space Marines, hundreds deep, and the shrinking ring of fighting warriors stood atop the mound, battling like heroes of legend.