When he heard the sounds, they were faint at first, barely registering over the ever present crackle of flames and relentless booms of explosions. The clash of blades quickly penetrated the dull miasma of war, and Solomon picked up his pace as he realised that the eastern approaches to the palace must be under attack.

Solomon ran as fast as his injuries would allow him, the pain of his burnt flesh acute, rendering his every footfall agonising. The sound of battle grew more strident and he could pick out the sharp clang of sword blades, though he dimly registered that there was no gunfire, no explosions.

The sounds came from ahead. Solomon skidded into a brightly lit dome, sunlight catching on the blades of the warriors who battled within. Captain Lucius commanded this sector of the defences with around thirty warriors, and Solomon saw the lithe figure of the swordsman at the centre of a tremendous battle.

Bodies littered the floor and a struggling mass of Emperor's Children filled the dome, surrounding Lucius as he fought for his life.

'Lucius!' cried Solomon raising his weapon and rushing to the swordsman's aid.

A flash of steel licked out and a warrior fell, cloven from neck to groin by the energised edge of Lucius's blade.

'They're breaking in, Solomon!' shouted Lucius gleefully, taking the head from another of his attackers with a deadly high cut.

'Not while I have my strength they won't!' bellowed Solomon, swinging his blade at the nearest of the attackers. His blow smashed the traitor to the ground in a welter of blood and shattered armour.

'Kill them all!' shouted Lucius.

'You dare return to me in failure?' bellowed Horus, the bridge of the Vengeful Spirit shaking with the fury of his voice. His face twisted in anger, and Fulgrim smiled as he watched the Warmaster struggle to hold his Cthonic fury in check. The Vengeful Spirit had changed a great deal since Fulgrim had last stood in the Warmaster's inner sanctum, its once open and brightly lit hubbub replaced with something far darker.

'Do you even understand what I am trying to do here?' continued Horus. 'What I have started at Isstvan will consume the whole galaxy, and if it is flawed from the outset then the Emperor will break us!'

Fulgrim allowed a smile of delicious insouciance to surface on his face, the excitement of finally arriving at Isstvan III, and the scale of the carnage wrought below, stimulating his taste for the excessive. Though the Pride of the Emperor had but recently arrived, Fulgrim had been careful to appear before the Warmaster as magnificent as ever, his exquisite armour worked with fresh layers of vivid purples and gold, with many new embellishments and finery added to complement the bright colours. His long white hair was pulled back, and his pale cheeks were marked with the beginnings of tattoos that Serena d'Angelus had designed for him.

'Ferrus Manus is a dull fool who would not listen to reason,' said Fulgrim. 'Even the mention of the Mechanicum's pledge did not—'

'You swore to me that you could sway him! The Iron Hands were essential to my plans. I planned Isstvan III with your assurance that Ferrus Manus would join us. Now I find that I have yet another enemy to contend with. A great many of our Astartes will die because of this, Fulgrim.'

'What would you have had me do, Warmaster?' smiled Fulgrim, being sure to twist his words with a sly mocking tone. 'His will was stronger than I anticipated.'

'Or you simply had an inflated opinion of your own abilities.'

'Would you have had me kill our brother, Warmaster?' asked Fulgrim, hoping that Horus would not ask such a thing of him, but knowing that it was what he wanted to hear. 'For I will if that is what you desire of me.'

'Perhaps I do,' replied Horus unmoved. 'It would be better than leaving him to roam free to destroy our plans. As it is, he could reach the Emperor or one of the other primarchs and bring them all down on our heads before we are ready.'

'Then if you are quite finished with me, I shall return to my Legion,' said Fulgrim, turning away with a flourish calculated to infuriate the Warmaster. He was not to be disappointed, and felt his heart pound as Horus said, 'No, you will not. I have another task for you. I am sending you to Isstvan V. With all that has happened, the Emperor's response is likely to arrive more quickly than anticipated and we must be prepared for it. Take a detail of Emperor's Children to the alien fortresses there and prepare it for the final phase of the Isstvan operation.'

Fulgrim recoiled and turned back to his brother, the disgust at such a menial role horrifying and repugnant. The exquisite sensations flooding his body at his baiting of the Warmaster faded and left him hollow inside. 'You would consign me to the role of castellan, as some housekeeper making your property ready for your grand entrance? Why not send for Perturabo? This kind of thing is more to his liking.'

'Perturabo has his own role to play,' said Horus. 'Even now, he prepares to lay waste to his home world in my name. We shall be hearing more of our bitter brother very soon, have no fear of that.'

'Then give this task to Mortarion!' spat Fulgrim. 'His grimy footsloggers will relish an opportunity to muddy their hands for you! My Legion was the chosen of the Emperor in the years when he still deserved our service. I am the most glorious of his heroes and the right hand of this new Crusade. This is… this is a betrayal of the very principles for which I chose to join you, Horus!'

'Betrayal?' said Horus, his voice low and dangerous. 'A strong word, Fulgrim. Betrayal is what the Emperor forced upon us when he abandoned the galaxy to pursue his quest for godhood and gave over the conquests of our Crusade to scriveners and bureaucrats. Is that the charge you would level at me, to my face, on the bridge of my own ship?'

Fulgrim stepped back, his anger fading as he felt Horus's rage wash over him, relishing the crawling sensations that filled him at the excitement of the confrontation. 'Perhaps I do, Horus. Perhaps someone needs to tell you a few home truths, now that your precious Moumival is no more.'

'That sword,' said Horus, indicating the venom sheened weapon that Fulgrim had been given at their last meeting. 'I gave you that blade as a symbol of my trust in you, Fulgrim. We alone know the true power that lies within it. That weapon almost killed me, and yet I gave it away. Do you think I would give such a weapon to one I do not trust?'

'No, Warmaster,' said Fulgrim.

'Exactly The Isstvan V phase of my plan is the most critical,' said Horus, and Fulgrim could feel the Warmaster's superlative diplomatic skills coming to the fore as the dangerous embers of his ego were fanned.

'Even more so than what is happening below us. I can entrust it to no other. You must go to Isstvan V, my brother. All depends on your success.'

Fulgrim let the violent potential crackling between them continue for a long, frightening moment, before laughing. 'And now you flatter me, hoping my ego will coerce me into obeying your orders.'

'Is it working?' asked Horus.

'Yes,' admitted Fulgrim. 'Very well, the Warmaster's will be done. I will go to Isstvan V'

'Eidolon will stay in command of the Emperor's Children until we join you,' said Horus, and Fulgrim nodded.

'He will relish the chance to prove himself further,' said Fulgrim.

'Now leave me, Fulgrim,' said Horus. 'You have work to do.'

Fulgrim turned smartly and marched from the Warmaster's presence, his breathing coming in shallow bursts as he replayed the violent potential of the near confrontation and allowed the memory of his brother's anger once more to stimulate his senses.

The feeling was sublime, and he imagined greater and headier delights ahead when the Isstvan V portion of the Warmaster's plan came to fruition: such horrors, such death, such delights.