Originally Posted by Brother Oni
Bonus GrimDark points if the good Father has stumbled on a genestealer coven and is now infected. You could do a couple story sections of the Father's spectacular fall from grace and subsequent retirement into seclusion, then his coming back with a new reformed cult of the Emperor, with a message of the sinful to redeem themselves in the Emperor's light (the Father should know, right?) and has an amazing conversion rate of new followers.
Let the story sit for a while, then make mention of the new civil war on the planet and a bit later, the subsequent discovery of a genestealer infestation (which the players can either join in on the shooting, help supply Imperial forces, or steer well clear).
Nice one. Genestealer infestations are always fun.
Hmm... Do the 40k rulebooks have rules for the players getting infected? Now, for novices, you'd probably have to just kill the character, but if someone's a good enough role-player... Could make for an interesting story...