He pulled open the hatch where the flight officers and hardwired pilots fought to bring them in through the swirling yellow storm clouds. He could hear the same, repeating phrase coming over the internal speakers here.

'Where's it coming from?' he demanded.

The nearest flight officer turned and said, 'It's a vox, plain and simple, but…'

'But?'

'It's coming from a ship vox,' said the man, pointing at a wavering green waveform on the waterfall display before him. 'From the patterning it's one of ours. And it's a powerful one, a transmitter designed for inter-ship communication between fleets.'

'It's an actual vox transmission?' said Loken, relieved it wasn't ghost chatter like the hateful voice of Samus.

'Seems to be, but a ship's vox unit that size shouldn't be anywhere near the surface of a planet. Ships that big don't come this far down into the atmosphere. Leastways if they want to keep flying they don't.'

'Can you jam it?'

'We can try, but like I said, it's a powerful signal, it could burn through our jamming pretty quickly.'

'Can you trace where it's coming from?'

The flight officer nodded. 'Yes, what won't be a problem. A signal that powerful we could have traced from orbit.'

'Then why didn't you?'

'It wasn't there before,' protested the officer. 'It only started once we hit the ionosphere.'

Loken nodded. 'Jam it as best you can. And find the source.'

He turned back to the crew compartment, unsettled by the uncanny similarities between this development and the approach to the Whisperheads.

Too similar to be accidental, he thought.

He opened a channel to the other members of the Moumival, receiving confirmation that the signal was being heard throughout the speartip.

'It's nothing, Loken,' came the voice of the Warmaster from the Stormbird at the leading edge of the speartip. 'Propaganda.'

'With respect, sir, that's what we thought in the Whisperheads.'

'So what are you suggesting, Captain Loken? That we turn around and head back to Davin? Ignore this stain on my honour?'

'No, sir,' replied Loken. 'Just that we ought to be careful.'

'Careful?' laughed Abaddon, his hard Cthonic laughter grating even over the vox. 'We are Astartes. Others should be careful around us.'

'The first captain is right,' said Horus. 'We will lock onto this signal and destroy it.'

'Sir, that might be exactly what our enemies want us to try.'

'Then they'll soon realise their error,' snapped Horus, shutting off the connection.

Moments later, Loken heard the Warmaster's orders come through the vox and felt the deck shift under him as the Stormbirds smoothly changed course like a pack of hunting birds.

He made his way back to his cage seat and strapped himself in, suddenly sure that they were walking into a trap.

'What's going on, Garvi?' asked Vipus.

'We're going to destroy that voice,' said Loken, repeating the Warmaster's orders. 'It's nothing, just a vox transmitter. Propaganda.'

'I hope that's all it is.'

So do I, thought Loken.

The Stormbird touched down with a hard slam, lurching as its skids hit soft ground and fought for purchase. The harness restraints disengaged and the warriors of Locasta smoothly rose from their cage seats and turned to retrieve their stowed weaponry as the debarking ramp dropped from the rear of the Stormbird.

Loken led his men from their transport, hot steam and noxious fumes fogging the air as the blue glow of the Stormbird's shrieking engines filled the air with noise. He stepped from the hard metal of the ramp and splashed down onto the boggy surface of Davin's moon. His armoured weight sank up to mid calf, an abominable stench rising from the wet ground underfoot.

The Astartes of Locasta and Brakespur dispersed from the Stormbird with expected efficiency, spreading out to form a perimeter and link up with the other squads from the Sons of Horus.

The noise of the Stormbirds diminished as their engines spooled down and the blue glow faded from beneath their wings. The billowing clouds of vapour they threw up began to disperse and Loken had his first view of Davin's moon.

Desolate moors stretched out as far as the eye could see, which wasn't far thanks to the rolling banks of yellow mist clinging to the ground and moist fog that restricted visibility to less than a few hundred metres. The Sons of Horus were forming up around the magnificent figure of the Warmaster, ready to move out, and spots of light in the yellow sky announced the imminent arrival of the Army drop ships.

'Nero, get some men forward to scout the edges of the mist,' Loken ordered. 'I don't want anything coming at us without prior warning.'

Vipus nodded and set about establishing scouting parties as Loken opened a channel to Verulam Moy. The Captain of the 19th Company had volunteered some of his heavy weapon squads and Loken knew he could rely on their steady aim and cool heads. Verulam? Make sure your Devastators are ready and have good fields of fire, they won't get much of a warning through this fog.'

'Indeed, Captain Loken,' replied Moy. 'They are deploying as we speak.'

'Good work, Verulam,' he said, shutting off the vox and studying the landscape in more detail. Wretched bogs and dank fens rendered the landscape a uniform brown and sludgy green, with the occasional blackened and withered tree silhouetted against the sky. Clouds of buzzing insects hovered in thick swarms over the black waters.

Loken tasted the atmosphere via his armour's external senses, gagging on the rank smell of excrement and rotten meat. The senses in his armour's helmet quickly filtered them out, but the breath he'd taken told him that the atmosphere was polluted with the residue of decaying matter, as though the ground beneath him was slowly rotting away. He took a few ungainly steps through the swampy ground, each step sending up a bubbling ripple of burps and puffs of noxious gasses.

As the noise of the Stormbirds faded, the silence of the moon became apparent. The only sounds were the splashing of the Astartes through the swampy bogs and the insistent buzz of the insects.

Torgaddon splashed towards him, his armour stained with mud and slime from the swamps and even though his helmet obscured his features, Loken could feel his friend's annoyance at this dismal location.

'This place reeks worse than the latrines of Ullanor,' he said.

Loken had to agree with him, the few breaths he'd taken before his armour had isolated him from the atmosphere still lingered in the back of his throat.

'What happened here?' wondered Loken. 'The briefing texts didn't say anything about the moon being like this.'

'What did they say?'

'Didn't you read them?'

Torgaddon shrugged. 'I figured I'd see what kind of place it was once we landed.'

Loken shook his head, saying, 'You'll never make an Ultramarine, Tarik.'

'No danger of that,' replied Torgaddon. 'I prefer to form plans as I go and Guilliman's lot are even more starch-arsed than you. But leaving my cavalier attitude to mission briefings aside, what's this place supposed to look like then?'

'It's supposed to be climatologically similar to Davin - hot and dry. Where we are now should be covered in forests.'

'So what happened?'

'Something bad,' said Loken, staring out into the foggy depths of the moon's marshy landscape. 'Something very bad.'