Warhammer 40k - Horus Heresy Novella - Scorched Earth by Nick Kyme

Nearly a quarter of a million loyal Space Marines lost their lives on Isstvan V – the Dropsite Massacre lasted only a few hours, and yet the Iron Hands, Raven Guard and Salamanders were slaughtered by those they had once called kin. With the disappearance of their primarch weighing heavily upon their hearts, Ra'stan and Usabius of the XVIIIth Legion leave behind their fellow survivors and strike out into the Urgall Depression. Their mission: to find what, if anything, remains of mighty Vulkan...