Far below them, he could see the. glittering lights of the Imperial deployment zone where they had first made planetfall on Davin, a wide circle of arc lights, makeshift landing platforms and defensive positions. The pilot brought them in at a steep angle, speed more important to Loken than any notion of safe flight, and they streaked past scores of other landing craft on their way to the surface.

'Why so many?' wondered Loken as their flight levelled out and they shot past the wide circle of light, seeing soldiers and servitors toiling to expedite the approach of so many landing craft.

'No idea,' said the pilot, 'but there's hundreds of them coming down from the fleet. Looks like a lot of people want to see Davin.'

Loken didn't reply, but the sight of so many landing craft en route to Davin was yet another piece of the puzzle that he didn't understand. The vox networks were jammed with insane chatter, weeping voices and groups claiming that the end was coming, while yet others gave thanks to the divine Emperor that his chosen champion would soon rise from his deathbed.

None of it made any sense. He'd tried to make contact with the Mournival, but no one was answering, and a terrible foreboding filled him when he couldn't even reach Maloghurst on the Vengeful Spirit.

Their flight soon carried them beyond the Imperial position, and Loken saw a ribbon of light stretching north from the landing zone. A host of pinpricks of light pierced the darkness, and Loken ordered the pilot to fly lower and reduce speed.

A long column of vehicles: tanks, supply trucks, transporter flatbeds and even some civilian traffic, drove along the dusty hardpan, each one swamped with people, and all heading to the mountains as fast as their engines could carry them. The Thunderhawk powered on through the fading light of day, soon losing sight of the column of vehicles that was heading in the same direction.

'How long until we reach the Warmaster's position?' he asked.

'At current speed, maybe ten minutes or so,' answered the pilot.

Loken tried to collect his thoughts, but they had long since derailed in the midst of all this madness. Ever since leaving the interex, his mind had been a whirlpool, sucking in every random thought and spitting it out with barbs of suspicion. Could it be that he was still suffering the after-effects of what had happened to Jubal? Might the power, unlocked beneath the Whisperheads, be tainting him so that he jumped at shadows where none existed?

He might have been able to believe that, but for the presence of the anathame and his certainty that First Chaplain Erebus had lied to him on the voyage to Davin.

Karkasy had said that Erebus wanted Horus to come to Davin's moon, and his undoubted complicity - in the theft of the anathame could lead to only one conclusion. Erebus had wanted Horus to be killed here.

That didn't make any sense either. Why go to such convoluted lengths just to kill the Warmaster, surely there had to be more to it than that…

Facts were slowly accumulating, but none of them fit, and still he had no idea why any of this was happening, only that it was, and that it was by the artifice of human design. Whatever was going on, he would uncover the conspiracy and make those involved pay with their lives.

'We're coming up on the Warmaster's Stormbird,' called the pilot.

Loken shook himself from his venomous reverie. He hadn't been aware of time passing, but immediately turned his attention to what lay beyond the armoured glass of the cockpit.

Tall mountain peaks surrounded them, jagged cliffs of red stone, veined with gleaming strata of gold and quartz. They followed the course of an ancient causeway along the valley, its flagstones split and cracked with the passing of the centuries. Statues of long-dead kings lined the processional way, and toppled columns littered this forgotten highway like fallen guardians. Shadows plumbed the depths of the valley along which they flew and in a gap ahead, he could see a reflected glow in the brazen sky.

The pilot dropped their speed and the gunship flew through the gap into a colossal crater gouged from the landscape like an enormous, flat-bottomed basin. The sheer sides of the crater soared above them, its diameter thousands of metres across.

A huge stone building stood at its centre, carved from the same rock as the mountains and bathed in the light of a thousand flaming torches. The Thunderhawk circled the structure and Loken saw that it was a giant octagonal building, each corner shaped like the bastion of a fortress. Eight towers surrounded a wide dome at its centre and flames burned from their tops.

Loken could see the Warmaster's Stormbird below them, a multitude of torchbearers surrounding it, hundreds, maybe even thousands of people. A clear path stretched from the Stormbird towards the cyclopean archway that led into the building, and Loken saw the unmistakable form of the Warmaster being borne by the Sons of Horus towards it.

'Take us down. Now!' shouted Loken. He rose, made his way back to the crew compartment and snatched his bolter from the rack.

'What's up?' asked Vipus. 'Trouble?'

'Could be,' said Loken, turning to address all the warriors aboard the gunship. 'Once we disembark, take your lead from me.'

His warriors had efficiently prepped for a combat disembarkation, and Loken felt the motion of the Thunderhawk change as it slowed and came in to land. The internal light changed from red to green and the craft slammed hard into the ground. The assault ramp dropped and Loken led the way out, marching confidently towards the building.

Night had fallen, but the air was hot, and the sour fragrances of bitter blossoms filled the air with a beguiling, aromatic scent. He led his men onwards at a quick march. Many of the torchbearers turned quizzically towards them, and Loken now saw that these were the indigenous inhabitants of Davin.

The Davinites were more wiry than most mortal men, tall and hirsute with thin limbs, and elaborate topknots worn in a style similar to Abaddon's. They wore long capes of shimmering, patterned scales, banded armour - of the same lacquered scales - and most were armed with cross-belts of daggers and primitive looking black powder pistols. They parted before the advance of the Astartes, heads bowed in supplication, and it forcibly struck Loken just how close to deviancy these creatures appeared to be.

He hadn't paid much attention to the Davinites the first time he'd landed. He was just a squad captain more concerned with obeying orders and completing the tasks assigned to him than paying attention to the locals. Even this time, his attention had been elsewhere, and the almost bestial appearance of the Davinites had more or less slipped past his notice.

Surrounded by hundreds of the planet's inhabitants, their divergence from the human genome was unmistakeable, and Loken wondered how they had avoided extermination six decades ago, especially since it had been the Word Bearers who had made first contact with Davin - a Legion not noted for its tolerance of anything beyond the norm.

Loken was reminded of Abaddon's furious argument with the Warmaster over the question of the interex, and of how the first captain had demanded that they make war upon them for their tolerance of xenos breeds. If anything, Davin was far more of a textbook case for war, but somehow that hadn't happened.

The Davinites were clearly of human gene-stock, but this offshoot of humanity had diverged into a species almost all of its own. The wide spacing of their features, the dark eyes without pupils and the excessive, almost simian volume of thick hair on their faces and arms put Loken more in the mind of the stable-bred mutants some regiments of the Imperial Army employed. They were crude creatures with the intelligence to swing a sword or fire a clumsy rifle, but not much else.