It was a legendary time.... The Great Crusade carried the light of Imperial Truths to the darkest corners of the Galaxy, bringing back the disparate worlds of humanity to the bosom of the Empire and erasing alien races from the face of history. By the will of the blessed Emperor, who decided to withdraw from military affairs, the reins of this unprecedented campaign were awarded to Horus, the primar of the Legion of Moon Wolves. This is what the chronicles say, but in none of them can find the answer to the question - when, under the sky of what world the seeds of the Great Heresy sprouted . Maybe it was the day Horus killed the Emperor for the first time.