User blog comment:Solomus-BlackWing/A Legacy/@comment-4964060-20140415220647/@comment-24753384-20140415221309

A sub-Sector completely fallen to Chaos, they some how hide it (if its possible) then a Imperial Guard battle group goes there for some reason or another? This battle group is corrupted so a fairly big Chaos army is forming. Behind the scenes is a Chaos Lord trying to become a demon Prince with his small band of marines pulling the strings.

So this inquisition cabal is formed to stop the threat and make sure it does not arise again but not exterminatus-ing everything.