The Gray Knights are all humanity has to counter the might of Chaos. Founded in deep secrecy, this Chapter of the Adeptus Astartes dates back to the troubled times of the Horus Heresy. War Chamber of the Inquisition, legendary demon slayers march into hell - and beyond - in pursuit of their supernatural enemies. After enduring the intense psychological training that the order's recruits undergo in a secret fortress on Titan, these super warriors join a brotherhood capable of resisting the Ruinous Powers. On the planet Armageddon, the Gray Knights will have to prove this again.