On the black sands of Isstvan V, Gabriel Santar is dying. Struck down by his former battle-brother, Julius Kaesoron of the Emperor’s Children, he watches helplessly as his father Ferrus Manus is murdered by the thrice-damned traitor Fulgrim. But Santar’s fading sight reveals far more about the supposedly perfect Phoenician primarch than anyone could have guessed – is it too late for this revelation to have any value to the Iron Hands Legion? You can't miss the death of a primarch - the metal-armed, c'tan-killer Ferrus Manus no less. These gods among men might seem invincible, but not at the hands of their brother primarchs. And Manus’s murderer reveals just how far the manipulative and insidious powers of Chaos can reach.