Nearly a quarter of a million loyal Space Marines died on Isstvan V. The slaughter at the landing lasted only a few hours, yet the Iron Hands, the Raven Guard and the Salamanders were killed by those whom they once called brothers. With the disappearance of the primarch—a crushing burden on Ra’stan and Uabisius’ hearts from the XVIII Legion—they left their surviving brothers behind and headed for the Urgal Trench. Their mission: to find what remains of the mighty Vulkan…