In the wake of the Dropsite Massacre at Isstvan V, the survivors of the Salamanders Legion searched long and hard for their fallen primarch, but to no avail. Little did they know that while Vulkan might have wished himself dead, he lives still. As the war continues without him, all eyes turn to Ultramar and Guilliman's new empire there, and Vulkan's sons are drawn into an insidious plot to end the Heresy by the most underhand means imaginable.