 As the Heresy is getting under way, the outwardly still loyal Warmaster orders the entire 9th Legion and their unsuspecting Primarch to a remote star system.There they find themselves isolated and ambushed, fighting a new kind of war against Chaos entities and daemons designed to trigger the Legion's flaw.The plan almost succeeds; yet conflicting agendas among anti-Imperial protagonists, as well as the fortitude and unorthodox tactics of quick-to-adapt Blood Angels, narrowly result in Loyalist victory.