This detailed sourcebook tells of the Achilus Crusade and the great challenges it faces from both without and within. Living up to the ideals of honor, brotherhood, and duty is a difficult task, and it is the fate of the Deathwatch Space Marines in the Jericho Reach to shoulder this duty head-on they are the first and last line of defense against a myriad of threats to the Crusade of which some commanders are not even aware.