After the devastation of his Legion in the killing fields of Isstvan V, Primarch Corax approved an accelerated implantation process to create new Raven Guard - a process secretly disrupted by his enemies. But despite their terrible mutations, the Raptor warriors are still ready to carry out the orders of their primarch. When an observant pack of Space Wolves legionnaires unexpectedly arrives, Lieutenant Navar Hef must meet his warlike brethren and discover if they can hide their own flaws...