'And this is the Mournival?'

'They are, and for all their damned horseplay, they are invaluable to me. They are a voice of reason in my ear when all around me is confusion. They are as dear to me as my brother primarchs and I value their counsel above all others. In them are the humours of choler, phlegm, melancholia and sanguinity mixed in exactly the right amount I need to keep me on the side of the angels.'

'So they are advisors?'

'Such a term is too bland for the place they have in my heart. Learn this, Petronella Vivar, and your time with me will not have been in vain: without the Mournival, the office of Warmaster would be a poor thing indeed.'

Horus stepped forward and pulled something from his belt, something with a long strip of parchment drooping from it.

'My sons,' said Horus, dropping to one knee and holding the waxen token towards the Mournival. 'Would you hear my oath of moment?'

Stunned by the magnanimity of such an act, none of the Mournival dared move. The other Astartes on the embarkation deck saw what was happening and a hush spread throughout the chamber. Even the background noise of the deck seemed to diminish at the incredible sight of the Warmaster kneeling before his chosen sons.

Eventually, Loken reached out a trembling gauntlet and took the seal from the Warmaster's hand. He glanced over at Torgaddon and Aximand either side of him, quite dumbfounded by the Warmaster's humility.

Aximand nodded and said, 'We will hear your oath, Warmaster.'

'And we will witness it,' added Abaddon, unsheathing his sword and holding it out before the Warmaster.

Loken raised the oath paper and read the words the commander had written.

'Do you, Horus, accept your role in this? Will you take your vengeance to those who defy you and turn from the glory of all you have helped create? Do you swear that you shall leave none alive who stand against the future of humanity and do you pledge to do honour to the XVI Legion?'

Horus looked up into Loken's eyes and removed his gauntlet, clenching his bare fist around the blade Abaddon held out.

'On this matter and by this weapon, I swear,' said Horus, dragging his hand along the sword blade and opening the flesh of his palm. Loken nodded and handed the wax seal to the Warmaster as he rose to his feet.

Blood welled briefly from the cut and Horus dipped the oath paper in the clotting red fluid before affixing the oath paper to his breastplate and grinning broadly at them all.

'Thank you, my sons,' he said, coming forward to embrace them all one by one.

Loken felt his admiration for the Warmaster fill his heart, all the hurt at their exclusion from his deliberations on the way here forgotten as he held each of them close.

How could they ever have doubted him?

'Now, we have a war to wage, my sons,' shouted Horus. 'What say you?'

'Lupercal!' yelled Loken, punching the air.

The others joined in and the chant spread until the embarkation deck reverberated with the deafening roars of the Sons of Horus.

'Lupercal! Lupercal! Lupercal! Lupercal!'

The Stormbirds launched in sequence, the Warmaster's bird streaking from its launch rails like a predator unleashed. At intervals of seven seconds, each Stormbird fired until all six were launched. The pilots kept them close to the Vengeful Spirit, waiting for the remaining assault craft to launch from the other embarkation decks. So far, there had been no sign of the Glory of Terra, Eugan Temba's flagship, or any of the other vessels left behind, but no one was taking any chances that their might be wolf pack squadrons of cruisers or fighters lurking nearby. Presently, another twelve Stormbirds of the Sons of Horus took up position with the Warmaster's squadron as well as two belonging to the Word Bearers. The formation complete, the Astartes craft banked sharply, altering course to take them to the surface of Davin's moon. The mighty, cliff-like flanks of the Warmaster's flagship receded and, like swarms of bright insects, hundreds of Army drop ships detached from their bulk transporters - each one carrying a hundred armed men.

But greatest of all were the lander vessels of the Mechanicum.

Vast, monolithic structures as big as city blocks, they resembled snub-nosed tubes fitted with a wealth of heat resistant technologies and recessed deceleration burners. Inertial dampening fields held their cargoes secure and explosive bolts on internal anti-motion scaffolding were primed to release on impart.

In the wake of the militant arm of the launch came the logistics of an invasion, ammunition carriers, food and water tankers, fuel haulers and a myriad other support vessels essential for the maintenance of offensive operations.

Such was the proliferation of craft heading for the surface that no one could keep track of them all, not even the bridge crew under Boas Comnenus, and thus the gold-skinned landing skiff that launched from the civilian bay of the Vengeful Spirit went unnoticed.

The invasion fleet mustered in low orbit, orbital winds clutching at streamers of atmospheric gases and spinning them in lazy coils beneath the vessels.

As always, it was the Astartes who led the invasion.

The way in was rough. Atmospheric disturbances and storms wracked the skies and the Astartes Stormbirds were tossed like leaves in a hurricane. Loken felt the craft vibrate wildly around him, grateful for the restraint harness that held him fast to his cage seat. His bolter was stowed above him and there was nothing to do but wait until the Stormbird touched down and the attack began.

He slowed his breathing and cleared his mind of all distractions, feeling a hot energy suffuse his limbs as his armour prepared his metabolism for imminent battle.

The warriors of Nero Vipus's Locasta squad and Brakespur squad surrounded him, immobile, yet representing the peak of humanity's martial prowess. He loved them all dearly and knew that they wouldn't let him down. Their conduct on Murder and Xenobia had been exemplary and many of the newly elevated novitiates had been blooded on those desperate battlefields.

His company was battle tested and sure.

'Garviel,' said Vipus over the inter-armour link. 'There's something you should hear.'

'What is it?' asked Loken, detecting a tone of warning in his friend's voice.

'Switch to channel 7,' said Vipus. 'I've isolated it from the men, but I think you ought to hear this.'

Loken switched internal channels, hearing nothing but a wash of grainy static, warbling and constant. Pops and crackles punctuated the hiss, but he could hear nothing else.

'I don't hear anything.'

'Wait. You will,' promised Vipus.

Loken concentrated, listening for whatever Nero was hearing.

And then he heard it.

Faint, as though coming from somewhere impossibly far away was a voice, a gargling, wet voice.

'…the ways of man. Folly… seek… doom of all things. In death and rebirth shall mankind live forever…'

Though he was not built to feel fear, Loken was suddenly and horribly reminded of the approach to the Whisperheads when the air had been thick with the taunting hiss of the thing called Samus.

'Oh no…' whispered Loken as the watery, rasping voice came again. 'Thus do I renounce the ways of the Emperor and his lackey the Warmaster of my own free will. If he dares come here, he will die. And in death shall he live forever. Blessed be the hand of Nurghleth. Blessed be. Blessed be…'

Loken hammered his fist against the release bolt on his cage seat and rose to his feet, swaying slightly as he felt a strange nausea cramp his belly. His genhanced body allowed him to compensate for the wild motion of the Stormbird, and he made his way swiftly along the ribbed decking towards the pilots' compartment, determined that they wouldn't walk blind into the same horror as had been waiting for them on Sixty-Three Nineteen.