'Be not afraid, you are amongst friends,' chuckled Horus. 'I have spoken to you all individually over the course of the war with the Technocracy, but this is the first time you have been gathered and I have openly spoken of our destiny. You shall be my war council, those to whom I entrust the furthering of my plan.'
Horus rose from his seat, continuing to speak as he circled the table.
'Take a moment and look at the face of the man sitting next to you. In the coming fight, he will be your brother, for all others will turn from us when we make our intentions plain. Brother will fight brother and the fate of the galaxy will be the ultimate prize. We will face accusations of heresy and cries of treason, but they will fall from us because we are right. Make no mistake about that. We are right and the Emperor is wrong. He has sorely misjudged me if he thinks I will stand by while he abandons his realm in his quest for godhood, and leaves us amid the destruction of his rampant ambition. '
'The Emperor commands the loyalty of millions of soldiers and hundreds of thousands of Astartes warriors. His battle fleets reach across the stars from one side of the galaxy to the other. The 63rd Expedition cannot hope to match such numbers or resources. You all know this to be the case, but even so, we have the advantage.'
'What advantage is that?' asked Maloghurst, exactly on cue.
'We have the advantage of surprise. No one yet suspects us of having learned the Emperor's true plan, and in that lies our greatest weapon. '
'But what of Magnus?' asked Maloghurst urgently, 'What happens when Leman Russ returns him to Terra?'
Horus smiled. 'Calm yourself, Mai. I have already contacted my brother Russ and illuminated him with the full breadth of Magnus's treacherous use of daemonic spells and conjurations. He was… suitably angry, and I believe I have convinced him that to return Magnus to Terra would be a waste of time and effort.'
Maloghurst returned Horus's smile. 'Magnus will not leave Prospero alive.'
'No,' agreed Horus. 'He will not.'
'What of the other Legions?' asked Regulus. 'They will not sit idly by while we make war upon the Emperor. How do you propose to negate them?'
'A worthy question, adept,' said Horus, circling the table to stand at his shoulder. 'We are not without allies ourselves. Fulgrim is with us, and he now goes to win Ferrus Manus of the Iron Hands over to our cause. Lorgar too understands the necessity of what must be done, and both bring the full might of their Legions to my banner.'
'That still leaves many others,' pointed out Erebus.
'Indeed it does, chaplain, but with your help, others may join us. Under the guise of the Chaplain Edict, we will send emissaries to each of the Legions to promulgate the formation of warrior lodges within them. From small beginnings we may win many to our cause.'
'That will take time,' said Erebus.
Horus nodded. 'It will, yes, but it will be worth it in the long term. In the meantime, I have despatched mobilisation orders to those Legions I do not believe we can sway. The Ultramarines will muster at Calth to be attacked by Kor Phaeron of the Word Bearers, and the Blood Angels have been sent to the Signus Cluster, where Sanguinius shall be mired in blood. Then we make a swift, decisive stroke on Terra.'
'That still leaves other Legions,' said Regulus.
'I know,' answered Horus, 'but I have a plan that will remove them as a threat to us once and for all. I will lure them into a trap from which none will escape. I will set the Emperor's Imperium ablaze and from the ashes will arise a new Master of Mankind!'
'And where will you set this trap?' asked Maloghurst.
'A place not far from here,' said Horus. 'The Istvaan system.'
~ TIMELINE ~
Humanity dominates Earth. Civilisations come and go. The Solar system is colonised. Mankind lives on Mars and the moons of Jupiter, Saturn and Neptune.
Mankind begins to colonise the stars using sub-light spacecraft. At first only nearby systems can be reached and the colonies established on them must survive as independent states since they are separated from Earth by up to ten generations of travel.
Invention of the warp-drive accelerates the colonising of the galaxy. Federations and empires are founded. First aliens encountered and first Alien Wars are fought. First human psykers scientifically proved to exist. Psykers begin to appear throughout human worlds.
First Navigators are born allowing human spaceships to make even longer, quicker warp-jumps. Mankind enters a golden age of enlightenment as scientific and technological progress accelerates. Human worlds unite and non-aggression pacts are secured with dozens of alien races.
Terrible warp-storms interrupt interstellar travel. Sporadic at first, the storms eventually prevent any warp-jumps being made. The incidence of human mutation increases rapidly. Mankind enters a dark period of anarchy and despair.
Human worlds ripped apart by civil wars, revolts, alien predation and invasion. Human psykers and other mutants dominate some worlds and these rapidly fall prey to warp-creatures. Humanity is on the brink of destruction.
Earth is conquered by the Emperor and enters an alliance with the Mechanicum of Mars. Finally the warp-storms abate and interstellar travel is possible again. The Emperor builds the Astronomican and creates the Space Marine Legions. Human worlds reunited by the Emperor in a Great Crusade that lasts for two hundred years.