It was over in a matter of moments. One second the entire world felt as though it were coming apart at the seams, and the next, everything was almost eerily silent. Nemiel lay on his back, trying to regain his bearings. Icons blinked on his helmet display, informing him that his autosensors and vox-unit were resetting. As his vision cleared, he saw tendrils of smoke rising from his scorched armour.

Slowly and carefully, he sat upright. There was smoke everywhere, rising from warehouses that had been set aflame by the blast wave. The four abandoned lascannons were gone; he looked about and found one smashed to pieces against the side of a building, but the rest had simply disappeared.

A squeal of static in his ears made him start as his vox-bead came back online. He was about to silence it again when he heard words coalesce out of the interference.

'Battle Force Alpha, this is Leonis!' spoke a familiar voice, hazy and hashed out by atmospheric ionization. 'Activate your teleport beacons and stand by!'

Nemiel scrambled to his feet. Leonis was the primarch's personal callsign. He looked about the smoke-stained road and saw Brother-Sergeant Kohl climbing to his feet, along with Vardus and Ephrial. 'Where is Brother Askelon?' he called. 'We've got to get back to the warehouses immediately!'

'Over here,' a voice answered weakly from down the side-lane where they'd originally come. Nemiel and Kohl rushed to the corner to see Askelon slowly pushing himself upright. His unprotected head had been badly burned by the blast, but somehow the Techmarine was still able to move.

They helped Askelon to his feet. He looked over at Kohl and tried to grin, his lips cracking. 'Looks like you'll have to carry me after all,' he gasped.

Kohl grabbed the Techmarine's arm and draped it over his shoulder, then took hold of Askelon's waist with his left hand. 'I could carry two of you without breaking a sweat,' the sergeant growled. 'You just keep an eye out for more of those damned skitarii, and let me do the rest.'

Nemiel grabbed Askelon's other arm and together they helped the Techmarine along. He could hear signals going back and forth across the Battle Force command channel, so he knew that at least some of the Dark Angels had survived Archoi's deadly ambush. He hoped there was an Apothecary still alive, for Askelon's sake.

They linked up with the rest of the squad and headed back towards the barracks buildings as quickly as they could. It was only then that Nemiel fully saw the devastation that the bombardment had wrought.

An enormous column of ash and smoke rose into the sky off to the north, where the volcano and the forge's centre used to be. The rising sun tinged the climbing column of debris in shades of blood red and fiery orange, whilst closer to the ground Nemiel could see thin veins of pulsing orange, tracks of real magma flowing like blood from the volcano's shattered flanks. Fires blazed out of control from horizon to horizon, consuming the shattered husks of wrecked buildings in a vast swathe surrounding the epicentre of the blast. For all intents and purposes, the forge complex had been destroyed.

It took more than half an hour to cover the five hundred metres back to the warehouses. They saw the towering form of Brother Titus first. His armour had been scorched - in some places the paint had been stripped away down to the bare metal - but he seemed otherwise undamaged. The warehouses themselves were ablaze, and the road was full of Astartes. A disturbingly long line of dead battle brothers were stretched out along the roadway to their left; the bodies were being tended to by one of the ground force's two Apothecaries, collecting the gene-seed for the future of the Legion. The second Apothecary was tending to an even larger number of wounded Dark Angels who were formed into small groups according to their parent squads on the right side of the roadway.

In the centre of the crowd stood the company commanders and senior squad leaders, gathered beneath the shadow of the great Dreadnought. In their midst stood a towering figure in gleaming armour, his head bare and his expression one of cold, righteous rage. Nemiel left Askelon in Brother-Sergeant Kohl's care and hurried over to join the primarch.

Lion El'Jonson was receiving the reports of the company commanders when Nemiel arrived. Jonson caught the Redemptor's eye and but said nothing until the two captains had finished tallying their dead and wounded. As near as Nemiel could determine, some thirty of the Astartes had been killed in the ambush and twice as many others seriously wounded before the last of the frenzied Praetorians had been killed. The sight of so many dead brothers filled him with grief and a cold, fathomless rage.

The primarch listened gravely to the captains' reports and then turned to Nemiel. 'We've a grim start to the day, Brother-Redemptor,' Jonson said. 'I hope you bring us better news.'

Without preamble, Nemiel delivered his report. He told Jonson everything they'd found during the night, from the site of Vertullus's likely murder to the discovery of the great siege guns at the Titan foundry and Archoi's foul treachery.

'I surmised as much when most of our scouts were destroyed by their own brand-new torpedoes,' Jonson said. He turned and glanced back at the towering plume of ash and smoke to the north. 'When we traced the source of the vox jamming it made Archoi's duplicity all too clear.'

'The Lords of Mars will be furious at the loss of such a venerable forge,' Nemiel said forebodingly.

Jonson turned back to the Redemptor, his green eyes blazing. 'Such is the fate of all traitors!' he snapped. The force of his anger was like a physical blow, as though he'd reached over and slapped Nemiel across the face. 'So Horus and the rest of his ilk will learn in due time.'

'We saw the debris of a ship falling to earth,' Nemiel ventured more carefully. 'I take it the rebels have returned.'

The primarch drew in a deep breath and sought to master his humours. He nodded. 'A much smaller force, this time, but sufficient to their needs,' he said tersely. 'Horus moved much more quickly than I expected and sent out an ad hoc force not too dissimilar from ours. We would have been hard pressed to defeat them as it was, but Archoi's treachery proved to be our undoing. All of our destroyers were lost, along with both grand cruisers and the strike cruiser Adzikel. After bombarding the forge and eliminating the source of the jamming, I ordered the rest of the battle group to withdraw to the edges of the system and then teleported myself down to join you.'

The news of the battle group's defeat sent a stir through the stoic Astartes. Nemiel gripped his crozius and straightened, remembering his duties to the Legion. 'While we live, we fight, my lord,' he said, his voice defiant. 'Though the storm rages and the foe gathers about us, we are unmoved. Let them come: we are the warriors of the First Legion, and we have never known defeat!'

Shouts of agreement rose from the assembled Dark Angels. Jonson smiled. 'Well said, Brother-Redemptor,' he replied. 'You are right. We've suffered some terrible blows, but the battle isn't over yet.'

'What would you have of us, my lord?' Nemiel asked.

Jonson cast his eyes to the north, towards the distant bulk of the assembly building. 'We fall back to the foundry,' he said. 'So long as we possess Horus's siege guns, the rebels won't risk an orbital bombardment.' When he turned back to the Astartes, his face was grim.

'Once we're in position, we need to fortify the sector as best we can, and prepare for the fight of our lives. Unless I'm very much mistaken, the Sons of Horus will be here soon.'