Something is festering in the shadows, and it's closer than you might think...
There are a multitude of threats to the lives of humanity in the 41st millennium. From bloodthirsty xenos from beyond the stars to the ever-present shadow of Chaos. However, perhaps the most insidious enemy of the Imperium of man is the one hiding within its very cities. The Genestealer Cults present one of the deadliest threats to human life. Not because of great power or skill, but because they can appear in even the most well-fortified of strongholds. Even Holy Terra, a fortress world long thought impregnable, is currently under assault from this hidden enemy.
The cults are a slow rot within the fabric of the Imperium, biding their time sometimes for generations. When they emerge, they sweep over unsuspecting worlds like a tide, screeching prayers to their four-armed god. Brother turns against brother, and even spouses might find themselves on the business end of a lasgun. The cults in a mad frenzy will sweep across their previous homeworld. Of course, this is all a tragic front. Their "loving" Patriarch is simply setting them up as the final course of the meal their true masters will soon have.
As ...