Tech-marine Harkus intoned the Chant of Dissolution upon the Thunderhawk's boarding umbilical and the shaped breaching charges that would blast their way through the alien vessel's hull. Chaplain Clausel led the Ultramarines in prayer, blessing each warrior's gun and blade. Uriel had ordered chainswords issued to everyone, knowing that the fighting was sure to get close and bloody. Uriel rejoined his men and drew his power sword, bowing to receive the chaplain's blessing.

'Dread Archon! I am detecting an energy build-up three hundred thousand kilometres directly in front of us!'

Kesharq hurried over to the warrior who had spoken and stared at the sensor returns in horror.

There was no mistaking the energy signature. An enemy ship was building power in its weapon batteries and preparing to fire.

'Hard to port, take us low over the planet. Lose him in the atmosphere!'

'Broadside batteries open fire!' ordered Tiberius. 'Engage a reverse port turn!'

The enormous vessel shuddered as the entire port broadside unleashed a hail of fire upon the eldar vessel. Tiberius gripped the edge of the pulpit as the mighty war vessel began turning to face its foe and bring its prow bombardment cannon to bear.

They might not be doing this by the book, but by the Emperor, they were going to do it with their biggest guns.

Each broadside battery hurled explosive, building-sized projectiles towards their target. But at such extreme range, most flew wide of the mark, detonating hundreds of kilometres from the Stormrider. Some shells exploded close, but caused no real damage save peppering the hull and mainsail with spinning fragments.

The ship nimbly altered course, its needle-nosed prow sweeping left and diving hard towards the planet's atmosphere. More shots were fired and a vast explosion blossomed above the ship's position as the strike cruiser's bombardment cannon entered the fray.

The Stormrider was an obsidian dart, knifing through the atmosphere of Caernus IV, its superior speed and manoeuvrability carrying it from the guns of its enemy.

The Vae Victus tried to match the turn and follow the Stormrider, but she was nowhere near as nimble as her prey.

The eldar vessel slowed as it angled away from Caernus IV. At this point, a ship was effectively blind as its sensors realigned from the fiery journey through the upper atmosphere.

As the Stormrider cleared the atmosphere, a streak of blue flashed upwards and settled in behind the tall sails of the graceful ship. The Thunderhawk's powerful cannons stitched a path of fire across the rear quarter of the vessel, blasting off bladed fins and barbed hooks.

Before the eldar ship could react, the Thunderhawk swooped in across its curved topside. Drill clamps fired from the gunship's belly, burrowing into the wraithbone hull of the Stormrider, and dragging the lighter assault craft down hard onto the eldar ship.

Tech-marine Harkus triggered the firing mechanism of the boarding umbilical and shouted, 'Fire in the hole!' as he detonated the shaped breaching charges at its end. Even through the armoured deck plates of the Thunderhawk, Uriel could feel the tremendous blast. He spun the locking handle and wrenched open the circular hatch that led through the umbilical towards the breach in the eldar vessel's hull.

Speed was essential now. Hit hard and hit fast.

'Ultramarines! With me!' he bellowed and dropped through the boarding umbilical.

Uriel hit the deck of the alien vessel and rolled aside as the next Ultramarine warrior slammed down behind him. He sprang to his feet and drew his power sword and bolt pistol in one fluid motion. He swept his pistol around the room as he took in his surroundings, a low-ceilinged room stacked with round containers.

He thumbed the activation rune on the hilt of his sword and the blade leapt with eldritch fire just as a pair of crimson-armoured warriors charged through an oval shaped doorway. Their armour was smooth and gleaming, adorned with glittering blades, and they carried long rifles with jagged bayonets.

'Courage and honour!' screamed Uriel, launching himself at the eldar warriors.

He smashed his power sword down on the first alien's collarbone, shearing him from neck to groin. The other alien stabbed with its bladed rifle and Uriel spun inside its guard. He hammered his elbow into his attacker's face, pulverising its helmet visor and breaking its neck.

He spared a glance behind him as more of the Ultramarines dropped through the hull breach. Pasanius was there, the blue-hot burner of his flamer roaring and ready to incinerate the enemies of the Emperor.

Uriel raised his power sword and yelled, 'The bridge!'

He sprinted through the doorway, finding himself in a narrow, shadowed corridor, with smooth walls that tapered to a point above his head.

A strange, truly alien aroma filled his senses, but he could not identify it. Two curving passages radiated forwards, their ends disappearing from sight.

Uriel picked the left hand corridor, and charged down its length.

He shouted, 'Pasanius with me! Dardino and Venasus take the right.'

Uriel heard the beat of footsteps from up ahead and saw dozens of the armoured warriors charging to intercept him. They carried the same bladed rifles and Uriel could see a number of larger, more dangerous weapons amongst their ranks.

Raising his flamer, Pasanius shouted, 'Get down!'

Uriel dropped and felt the whoosh of superheated promethium as it washed over him down the corridor. Alien screams echoed from the glassy walls as the liquid flames cooked their bodies within their armour and seared the flesh from their bones.

Uriel pushed himself to his feet and charged forwards, hurdling the burning corpses and leaping amongst the eldar. His sword slashed left and right and where he struck, aliens died. With a wild roar, the Ultramarines followed their captain, swords hacking and cutting amongst the aliens. Screaming, chainsaw-edged blades ripped through the flexible armour plates and flesh of the aliens with ease.

Chaplain Clausel bellowed the Canticles of Faith as he smote the aliens with his deadly crozius arcanum.

Uriel felt a close range blast of splinter fire impact on his arm. He ignored it, his armour absorbed the blast. Another blast slammed into his helmet and he snarled, spinning and beheading his attacker.

The last of the eldar died: the corridor had become a stinking charnel house.

None of the Ultramarines had fallen, though several bled from minor wounds. Pasanius fired short bursts of flame along a bend further down the corridor, deterring any counterattack. Uriel opened a vox-channel to his other squads. 'Dardino, Venasus. What's your status?' Venasus answered first, his voice steady and controlled despite the sounds of fierce battle raging around him. 'Strong resistance, captain. We have encountered what looks like a major defence point. Dardino is attempting to flank the aliens. I estimate six minutes until we overwhelm them.'

'Make it four! Ventris out.'

Gunfire spat towards the Ultramarines, ricocheting from the walls and filling the air with whickering splinters. The same type of splinters Uriel had dug from the church wall on Caernus IV.

Pasanius was on the ground, a dark, smoking hole punched in his shoulder guard. Uriel could hear the sergeant's cursing over the vox-net as the big man dragged himself away from the bend in the tunnel, never once releasing his grip on his flamer. Uriel could hear the sounds of more aliens moving to intercept them and thumbed a pair of frag grenades from his belt dispenser.

The weight of fire began to intensify and Uriel knew they had to keep pushing on lest the assault be halted in its tracks before it had even begun.