Uriel granted as a razor edged claw slashed through the armour on his thigh, tearing into the muscle and ripping down to his knee. He toppled backwards, the alien's claw tearing from his flesh in a wash of bright blood. Uriel kicked out, breaking its neck and pulled himself backwards. The reek of promethium in the corridor was intense and as Pasanius helped him to his feet, he snatched a grenade from his belt.

'Run!' he shouted, pushing Pasanius down the corridor and hurling the grenade back the way they had come.

Pasanius gripped his captain's arm and pulled him to the deck as the grenade detonated, filling the corridor with lethal, scything fragments and igniting the choking promethium fumes. Roiling flames exploded with a whoosh of roaring air and the entire corridor was engulfed in a fiery explosion that billowed along its length, incinerating everything in its path. Uriel felt the flames wash over him, watching the external temperature reading on his visor rocket skywards. But neither his nor Pasanius's armour failed them and as the lethal flame wall burnt out, they found themselves in a blackened, corpse-choked passageway, littered with charred alien limbs and burning pools of promethium.

The two Space Marines struggled to their feet as the sounds of battle continued to rage throughout their ship.

There was more death yet to be done.

Admiral de Corte watched the charging Mortis Probati close with the hive ship with a mixture of anger and admiration. The Mortifactors had broken his battle line, but by the Emperor they were courageous! The strike cruiser's bombardment cannon pounded the hive ship at, in spatial terms, point blank range, tearing great gouges in its hide.

The long feeder tentacles at the hive ship's rear lashed forward, swiping ponderously at the ship, but its captain swung his ship out of harm's way at the last possible second.

A host of bio-ships swung in behind the strike cruiser, blocking any escape as another cluster spun around and moved to attack. Bio acids and spurts of plasma struck the ship and flames erupted from her hull.

Inquisitor Kryptman watched the uneven battle with fierce pride, his knuckles white on the pommel of his cane. He spun to face de Corte. 'We must help them. Bring us about.'

'I cannot,' said de Corte. 'We are too far beyond them. It will be impossible to turn in time. We are manoeuvring to a position behind the hive ship as planned.'

'Do it!' snapped Kryptman, hammering his cane on the deck. 'Do it now!'

Kryptman spun to face the black uniformed Jaemar, the ship's commissar. 'You! Make him turn this Emperor forsaken ship around and support these brave warriors.'

Jaemar unholstered his pistol, cowed by Kryptman's reputation.

'The admiral is correct, lord inquisitor, commissar,' said de Corte's flag lieutenant, Jex Viert, moving to stand between Jaemar and his admiral. He placed his hand on the hilt of his sword, the threat clear. 'The image you are seeing is from our port surveyors. Even were the order given now, we will not be able to turn quickly enough to matter. In this respect, the Mortifactors are on their own.'

But Jex Viert was wrong.

Captain Payne, aboard the wounded Mariatus, shouted, 'For the Emperor!' as he gripped the arms of his command chair. The hive ship loomed large in the viewing bay and he knew that even if he survived this battle, he would be summoned before a court martial for disobeying a direct order. But with two of his ships put out of action by this monstrosity, he would have risked much more to avenge their gallant crews.

The Mariatus shuddered as blazing gouts of plasma fired from the hive ship drooled over her hull. Her guns hammered the alien monster, blowing chunks of its armoured carapace spinning into space and leaving a trail of seeping wounds along its mountainous body.

Ahead, he saw the graceful form of the Mortifactors' ship locked together with a thrashing beast with claws as big as a Battle Titan that raked its side and tore great swathes of its armour away. More bio-ships surrounded her, ready to sweep down and attack. Despite this, the massive cannon mounted on its prow continued to fire on the hive ship and though the heroism of the Space Marines was truly magnificent, there could only be one outcome.

Well, not if Payne and the Mariatus had anything to say about it.

Uriel raced to the bridge, hearing the desperate vox-traffic travelling between the ships of the fleet, dismayed at the sheer carnage unleashed. His armour was blackened and his leg flared painfully as he ran. The tyranid creatures were all dead and the damaged areas of the ship were finally secured.

He couldn't believe what the Mortifactors had done. Breaking the battle line and charging forward to engage the hive ship at close quarters was about as far from the teachings of the primarch as it was possible to get.

He mounted the steps to the bridge three at a time, sheathing his bloodied sword and sprinting through the arched entrance to the command bridge. Lord Admiral Tiberius turned as he entered, his face set in a mask of controlled fury.

'Uriel, thank the Emperor,' said the master of the Vae Victus.

'The boarders are repelled,' reported Uriel, staring in horror at the viewing bay as the Mortifactors' ship was slowly engulfed by the tyranid craft. Its bombardment cannon continued to fire, even as it was slowly being taken apart.

'What have they done?' he whispered.

Tiberius shook his head, words failing the ancient admiral. Then the battered shape of a Sword class frigate hove into view, trailing blazing plumes of venting plasma and golden streamers of sparks and freezing oxygen.

'Guilliman's blood, look!' shouted Philotas, as the prow of the Mariatus swung around and ploughed straight into the heart of the creature attacking the Mortis Probati.

The hull of the Imperial vessel buckled as it struck the hardened carapace of the tyranid creature, but its forward momentum could not be denied and it cracked through the flesh of the beast, spewing its bodily fluids all across the hull of the Space Marine vessel. It thrashed in its death agonies, releasing the strike cruiser and tumbled away with the Mariatus embedded deep within its body.

As valiant as the sacrifice of the Mariatus had been, there were tyranid ships aplenty to finish off the Mortis Probati, but before any could react to its unexpected survival, she unleashed a final shot from her bombardment cannon that struck a knotted growth tucked away at the rear of the hive ship. Bright liquid spurted from the wound like an enormous geyser and a visible shudder ran the length of the hive ship as the main synapse link to its attendant bio-ships was severed.

Kryptman saw the great wound spew the hive ship's lifeblood into space and the listless drifting of the drone ships that surrounded it. His eyes flickered from bio-ship to bio-ship as he saw them pause in their relentless attack.

'Their connection to the hive mind is severed!' yelled Kryptman, spinning to face de Corte so quickly he almost fell. 'We must attack before it is restored! Immediately!'

Admiral Bregant de Corte nodded to Lieutenant Viert, who still stood between him and Jaemar. 'Mister Viert, order all ships forward. Let's close and finish this beast.'

While the tyranid ships drifted in confusion, the captains of the Sword of Retribution, the Luxor, the Yermetov and the Argus all closed as quickly as possible, their gun decks loading and firing as fast as their crew chiefs could whip their gun gangs. The Vae Victus and Arx Praetora squadron swooped in and tore the underside of the tyranid vessel apart in a flurry of well-aimed fire. Fusillade after fusillade of explosive shells and lasblasts hammered the tyranid ship, pulverising vast sections of its carapace and spraying jets of ichor in all directions.