Of all the Astartes Legions, the most mysterious and unpredictable are the White Scars of the Primarch Jaghatai Khan. Born into a civilization that recognizes only honor, speed and fearsome loyalty, even during the galaxy-tearing Horus Heresy it was unclear whose side the White Scars would take. In that war, both sides hoped that the White Scars would take their side. But now, when the Alpha Legion has carried out an inexplicable and causeless attack on the troops of the White Scars and Space Wolves, the Khan must decide once and for all whether he will fight on the side of the Emperor or the Warmaster. Or he won’t fight on anyone’s side...