M41.999, the Era of Ending-
The Cadia System, the Imperium's fortress world before the Eye of Terror.
From birth, those who lived there could never raise their eyes to gaze at the stars, for above them loomed that terrifying Warp vortex.
Its warriors were the toughest and bravest in the Imperium. They had been stationed there for an immensely long time, defending the Imperium of Man behind them with their blood and loyalty.
Now, the shadow of the black fleet began to engulf the entire Cadia sector. The Chaos Warmaster had spent ten thousand years laying his plans. It was time to reap the harvest.
Across the regions surrounding the Cadia sector, Nurgle zombies poured endlessly out of the underhives. Typhus, herald of Nurgle, spread the virus across world after world. The valiant Imperial defenders fought to the death, yet were still swallowed by the tide, losing all ability to resist before the Plague Fleet even arrived.
The Night Lords also began their bloody massacres in the Scarus sector. These master assassins slipped freely through the shadows, tormenting every innocent Imperial citizen with unspeakable cruelty.
War began to spread through Segmentum Obscurus, and vast numbers of Chaos Cultists began welcoming their masters.
Upon world after world lay the sites of vile Chaos sacrificial rituals established by the Word Bearers Chapter.
Tens of thousands of living beings were slaughtered. The Word Bearers used their powerful Chaos sorcery to sacrifice countless innocent captives, then harnessed the violent disturbances of their agonizing deaths to breach the thick barrier between reality and the Warp.
Thus, the Warp descended upon the Cadia sector, and violent Warp storms swept across Cadia.
From the Eye of Terror emerged an immense Chaos Fleet.
Even the Imperium's mightiest naval fleet-the Gothic Fleet-was powerless before a Chaos Fleet of such