'I know that,' said Leonid.

'Speaking of which, have you been able to raise your man Hawke yet?' asked Eshara, looking towards the mountains.

Leonid frowned and shook his head. 'No, not yet. Magos Beauvais lost contact with Hawke just before the torpedo launched. Once the Adeptus Mechanicus got over their pique at having been kept out of the loop on that one, they went over the recordings and filtered the last few seconds through their cogitators. It seems that there was gunfire just before the signal was lost.'

'So you think Hawke is dead?'

'Yes, I believe he is,' nodded Leonid. 'Even if his attackers didn't kill him, the torpedo's engines would have.'

'A shame,' noted Eshara. 'I think I would have liked to meet Guardsman Hawke. He sounds like a most heroic individual.'

Leonid smiled. 'Had anyone used the words "Hawke" and "heroic" in the same sentence a month ago, I would have laughed at them.'

'An unlikely hero then?'

'The unlikeliest,' agreed Leonid.

Forrix sweated inside his armour, the heat and choking air of these tunnels an anathema to him after the planet's surface. The floor of the tunnel sloped down at a steep angle, rough-hewn steps leading into the sweltering depths of the mine. The red rock of this planet held the day's heat in a miser's grip, releasing it as night fell in baking waves. Scores of slaves had died of heat exhaustion already, but the tunnel was making swift progress.

Galleries already branched to either side of the main tunnel. Lined with explosives to blow the lip of the ditch, they would allow the attackers to descend into it. Beyond these branches, the tunnel dipped more steeply in order to pass under the ditch, where the drilling rigs pushed towards the main curtain wall. Once this tunnel was complete, further galleries would be constructed beneath a sizeable length of the wall's foundations and a vast quantity of explosives detonated to bring it crashing down.

Like the construction of the third parallel, it was dirty, thankless work and brought little glory to its builders. Forrix knew he was being punished, and the knowledge that his punishment was unjustified was a twisting knife in his gut. He had watched Honsou strutting around with the bionic arm that had once belonged to Kortrish, swaggering in his new-found favour. Did he not realise that it had been him, Forrix, who had nurtured his ambition, kept him hungry to prove himself? And this was how he was repaid, forced to toil like a slave, a beast. He, the captain of the First grand company, labouring in the depths of a mine!

How could things have reversed so suddenly? Less than a week ago, he had been pre-eminent in the Warsmith's eyes: credited with the swift capture of Tor Christo and honoured with the direction of the advancing saps and parallels. No matter that Kroeger had allowed the daemon engines to be destroyed! No matter that Honsou's incompetence had allowed the Imperials to launch an orbital torpedo at them.

With the Warsmith on the brink of greatness, being stuck down here was the very last place he needed to be.

Jharek Kelmaur had confessed the truth of the matter after the debacle in the battery. Forrix had gone to the sorcerer's tent with murder in his heart and stormed in, his power fist sheathed in lethal energies. He had lifted the shocked magicker from his feet and thrown him across his alchemist's table, where a bound figure writhed in gurgling pleasure.

'You knew!' stormed Forrix. 'You knew the Imperial Fists would come to this place. You knew and you did not tell us.'

Kelmaur picked himself up and rounded on Forrix, his hands spreading with the beginnings of a sorcererous incantation. Forrix smashed his fist into Kelmaur's belly, doubling him up, and lifted him from his feet.

'Do not waste your cantrips on me, sorcerer,' sneered Forrix, hurling Kelmaur to the ground and squatting beside him. He wrapped his gauntlet around Kelmaur's neck and bunched his power fist above the sorcerer's head, poised to pound his skull to destruction.

'You knew the Imperial Fists would come, did you not?'

'No! I swear!'

'You are lying to me, Kelmaur,' snapped Forrix. 'I saw the look on your face when you told the Warsmith that the defenders had not managed to send a warning. You lied to him, didn't you? There was a warning given, wasn't there?'

'No!' wailed Kelmaur. Forrix slammed his power fist into Kelmaur's face, deactivating the energy field at the last second. Kelmaur's nose broke and he spat bloody teeth.

'Do not lie to me again or I will keep the fist active next time,' warned Forrix.

'I did not… know exactly, but I feared there had been a signal sent. It was so weak I knew it could not have left the system and believed that no one would hear it.'

'But someone did, didn't they?'

'So it seems, but I took steps to try and prevent any intervention.'

'What steps?'

'I despatched the Stonebreaker to the system jump point to intercept any reinforcements.'

Forrix groaned at Kelmaur's foolishness. 'And it never occurred to you that this might well have allowed them to approach the planet in the first place? Your stupidity is galling.'

Forrix released the sorcerer and shook his head. 'Answer me this then, Kelmaur. Why are we here? Why does the Warsmith bid us attack this place? What drives us towards this citadel with such haste and, more importantly, what is happening to the Warsmith?'

The sorcerer did not answer immediately and Forrix reactivated his power fist. Kelmaur squirmed away, but not quickly enough. The Iron Warrior gripped his robes and dragged him to his feet.

'Speak!'

'I dare not!'

'You will tell me or you will die. Decide now,' snarled Forrix, drawing back his fist.

'Gene-seed!' wailed Kelmaur, the words tumbling from his lips in a desperate rush. 'This citadel is a secret bastion of the Adeptus Mechanicus. They store and monitor the purity of the Adeptus Astartes' gene-seed here. There is a laboratorium hidden beneath the citadel with enough genetic material to create legions of Space Marines! The Despoiler had given the task of its capture to the Warsmith in return for his ascension. If we are successful, the Warsmith ascends to daemonhood! If we fail, he will be destroyed, reduced to the mindless horror of spawndom, cursed to live forever as a writhing, mutated monstrosity.'

Forrix lowered Kelmaur as the implications of such a prize sank in.

Gene-seed. The most precious resource in the galaxy. With such a prize, there would be no limit to the Despoiler's power and his Black Crusades would carve a new empire from the ashes of the Imperium. The scale of such a vision astounded even Forrix's jaded senses.

Daemonhood! To become a creature of almost limitless potential, with the power of the warp to call your own, to be able to mould reality to your own ends and become master of a million souls. Such a prize was worth any cost and Forrix now understood the Warsmith's all-consuming need to break into the citadel. And if that meant sacrificing every warrior here to achieve those ends, then that was a small price to pay for immortality.

Such a prize would be worth risking everything for. To travel in realms beyond the ken of mortal men, where nothing was denied and every possibility could be played out was a dream Forrix could well understand. His flinty gaze locked with Kelmaur's.

'Tell no one what you have told me, or the Warsmith shall hear of your folly.'

'He would not believe you,' whined Kelmaur.

'That is irrelevant. If the Warsmith even suspects you have deceived him, he will kill you. You know this to be true,' promised Forrix, stalking from the tent.

Now, deep in the dim tunnels below the planet's surface, Forrix watched as a gang of emaciated slaves dragged back another load of excavated soil. The tunnel was advancing and soon the Iron Warriors would be inside the citadel.