The Galaxy is in flames.

The Emperor's glorious vision for humanity is in ruins. His favoured son, Horus, has turned from his father's light and embraced Chaos.

His armies, the mighty and redoubtable Space Marines, are locked in a brutal civil war. Once, these ultimate warriors fought side by side as brothers, protecting the galaxy and bringing mankind back into the Emperor's light. Now they are divided.

Brother turns against brother, sons against their father. Full half of The Emperor's mighty legions have betrayed him, dealing a mortal blow to 3 of his loyal legions on Istvaan V. War has begun, a conflict that will engulf mankind in fire. Treachery and betrayal have usurped honour and nobility. Assassins lurk in every shadow. Armies are gathering. All must choose a side or die.

The screams of the innocent, the pleas of the righteous resound to the cruel laughter of Dark Gods. Suffering and damnation await should the Emperor fail and the war be lost.

The age of knowledge and enlightenment has ended.
The Age of Darkness has begun.

You are a captain of the...
>Loyalists. You have chosen to remain loyal to The Emperor of Mankind, safeguarding his nascent Imperium from those who would seek to usurp, or destroy it. You fight a grim battle, but Horus and his madness must be stopped, no matter the cost.
>Traitors. You have turned your back on the Emperor, the petty tyrant. For good or worse you follow Horus, though there are whispers within the legions that there are other forces at play...
>Renegades. The Emperor and Horus be damned! You'll rebuke both sides, and fight for the only thing worth dying for in this galaxy, yourself. It'll be a long, hard road, but what other roads are there in this madness?