'Is this what I think it is?' he asked Beauvais.

'That depends on what you think it is, but I can tell you that it is a Glaive class, ground-launched orbital torpedo.'

'And what in the name of the High Lord's balls do you expect me to do with it?' spluttered Hawke.

'We want you to fire it, Guardsman Hawke,' explained Magos Beauvais.

Followed by nearly two thousand men, Castellan Prestre Vauban clambered over the lip of the citadel's ditch and sprinted towards the Iron Warriors' raised earthworks. There was no battle cry, no shout of rage, only the silence of soldiers who knew their only chance of survival was stealth.

The men's faces were smeared with soot and their sky blue uniform had been left in the barracks in favour of plain black flak jackets.

Leonid's storming parties spread out from the ditch, clustered around the demolition teams and Vauban knew that this attack was a desperate gamble indeed. But as his second-in-command had pointed out, they had no choice but to attempt to destroy the enemy guns. To not try would be to allow the Iron Warriors to pound them into dust.

A thrill of fear and exultation coursed through his veins at the prospect of battle, it had been too long since he had led men into combat.

He clutched his bolt pistol close to his chest, running crouched over, the breath heaving in his lungs. The traitor line was still a few hundred metres away. His breathing sounded hellishly loud and the thump of boots on the dusty earth was like the thunder of a Titan's tread, but so far the alarm had not been raised. Perhaps there was a chance this reckless attack might just succeed.

Even in the dim light, Vauban could see a head raised above the level of the ramparts of the enemy earthworks and counted down the seconds until the attack hit home.

All they needed was a little more time.

Uraja Klane pulled himself up to the ramparts of the earthworks and peered into the darkness, resting his rifle on the rough, earthen parapet. There was something happening in front of the works, but he couldn't quite see what. Lord Kroeger had charged them with the protection of these guns and he knew better than to disappoint his master. But the flickering lights and noise from the sprawling campsite made it difficult to make out anything.

Behind him, several hundred soldiers slept on the firing step or drank distilled spirits from tin mugs in their muddy dug-outs.

He glanced down and kicked Yosha awake. He had a pair of battered field glasses that could see in the dark, didn't he?

'Hey, Yosha, wake up, you useless piece of…' hissed Klane.

Yosha mumbled something foul and unintelligible, then rolled over. Klane kicked him again.

'Yosha, wake up, damn you. Gimme your goggles!'

'What?' slurred Yosha. 'My goggles?'

'Yeah, I think there's something out there.'

Yosha grumbled, but dragged himself to his feet, rubbing his eyes with filthy hands and yawning hugely. He peered out into the darkness.

'There's nothing out there,' he declared sleepily.

'Use your damn goggles, you idiot.'

Casting a scathing look at his comrade, Yosha pulled out a set of blackened and ancient field goggles. A bizarre protuberance slotted over the eyepiece and Yosha pulled it over his shaven head. He rested his chin on his hands and trained his gaze over the parapet.

'Well,' pressed Klane. 'You see anything?'

'Yeah,' whispered Yosha. 'There's something coming. Looks like—'

'Like what?'

'Like—'

Klane never got the chance to find out. A sharp, buzzing crack whipped by him and blasted the back of Yosha's head open in an explosion of blood and brains. Yosha crumpled slowly and toppled from the rampart.

'Khorne's teeth!' swore Klane, jerking back and switching his gaze from the headless corpse to the ground before the earthworks.

The whipping noise slashed past him again and a puff of earth exploded next to him.

Sniper!

Klane ducked down behind the parapet and cocked his rifle, his head working left and right to see other sentries dropping, no doubt picked off by Imperial snipers on the walls of the ravelin. He swore again. There must be an attack coming in!

He crawled along the firing step, clambering over sleeping bodies towards the alarm siren, and pulled himself up the timber spar where the flared bullhorn was bolted. He grabbed the cranking handle.

Klane heard booted steps approaching the parapet and realised he didn't have much time. He turned the squealing handle, the wailing cry from the bullhorn growing in volume as he spun it faster and faster. A shot blasted the timber beside him, showering him with splinters and he flinched, releasing the handle and taking up his rifle.

Thudding footsteps hit the soil of the earthworks below. Damned Imperials! He snarled, pleased to have this chance to kill. Scrabbling hands sounded on the far side of the parapet.

No bastard Guardsman was going to get past Uraja Klane!

He roared in hatred and rose to his feet, swinging his rifle around to find himself facing a giant warrior in yellow power armour with a crackling sword and scarlet Imperial eagle on his breastplate.

'What the f—' was all he had time to say before the Imperial Fists Space Marine clove him in two with his power sword.

Sirens screamed, piercing the night with their cries and Vauban knew that with the element of surprise lost they had only a limited time to achieve their objective before they would have to fall back. He climbed the steep exterior slope of the earthworks, using the butt of his pistol for purchase. His soldiers scrambled over the parapet with a roar of released fury.

A grenade detonated nearby, showering him with earth and he slipped, feet scrabbling for grip.

A gauntleted hand reached down and closed on his wrist, lifting him easily across the parapet in a single motion. He was deposited on the firing step beside a broken corpse, and swiftly drew his power sword. The Space Marine who had hauled him over the parapet turned and began firing a bolt-gun into a mass of enemy soldiers in red overalls. His brethren were pushing further into the entrenchments as the Imperial Guard scrambled over the parapet and into the battery.

'Thank you, Brother-Captain Eshara,' said Vauban breathlessly.

The Imperial Fists captain nodded, slammed a fresh magazine into his bolter and said, 'Thank me later. We have work to do,' before turning and charging from the firing step.

Gunfire and explosions lit the trenches and dug-outs of the battery with strobing light, screaming soldiers and wounded men providing a cacophonous backdrop to the attack. Hundreds of Jourans poured over the earthwork, killing anything in their path. The Chaos soldiery had been caught largely unawares, and the Imperial troops offered no quarter to the unready foe. Storming parties slaughtered the enemy soldiers, shooting them where they lay or stabbing them with bayonets as they scrambled for weapons.

Fifteen gigantic war machines were situated here, enormous howitzers and long cannons with barrels so wide a man could stand upright inside. Bronze plates embossed with skulls and unholy icons were fixed on each machine's flank, and thick chains looped around giant rings were securely bolted to their track units. There was a terrible sense of menace surrounding the siege engines and Vauban had a gnawing sense of wrongness in his gut. He knew without doubt that such blasphemous creations should never have been allowed to come into existence.

The Imperial Fists swept efficiently through the battery, securing its perimeters and killing the war machines' gunners. They established themselves in strong positions around the approach trenches and parallel, ready to hold off the inevitable counterattack.