Hi all. I have written a basic story arc for an upcoming game for my group and I hoped to get feedback and improvements from more experienced GMs.

The acolyte PCs (a cleric, guardsman and pysker) start their mission on a feudal world which is a relatively recent addition to the Imperium. Psykers are hated and feared, therefore persecuted, put on trail and burnt. Also, sections of the population reject the teachings of the Ecclesiarchy (although not always outwardly).

The PCs are sent to a remote township at the request of the district Constable (also a PC) who will know more background and hopefully stimulate some good roleplaying. A series of gruesome deaths have occurred and no leads have been established by the Constable. Citizens have also reported that a figure (of varying descriptions) has stalked and attacked unfortunates who venture out after dark.

The premise behind the story is that the local preacher, who is devoutly faithful to the Emperor, is secretly harbouring psychic potential. He knows of the heresy that has befallen many of the townsfolk and has been using his powers to manipulate members of the population into murdering the non-believers. This presents him with a solid alibi. When the dead are brought to the chapel to undergo the local burial rites, the preacher has been performing rituals to remove the souls of the victims which return to the town to torment the heretics.

I felt the fact that one of the players is also a psyker presented a good roleplaying opportuntity. The PC will sense the inherent abilities of the preacher, but how will they act upon it!? One wrong move and they could both end up the victims of a witch hunt. Will the PCs see the preacher as the threat or someone who is using his Emperor given gift to enact vengeance on the faithless!?

I also toyed with an additional strand to the plot which included a heretical member of local high society (a Duke or Lord) who has so far avoided the attentions of the inquisition. I thought that the preacher’s ultimate aim was to bring him to justice, but as this world has an ingrained fear of witches, the elite protect themselves with personal hexmagraphic wards preventing the preacher attacking him directly. I’m still not sure on this though.

Any help would be greatly appreciated. I hope I've made this pretty easy to understand, as plot twists aren't always easy to down on 'paper'.

Here's some feudal worlds in the Calixis Sector that might help you out.

Ichovor - http://wh40k.lexicanum.com/wiki/Ichovor
Acreage - http://warhammer40k.wikia.com/wiki/Acreage
Elros - http://wh40k.lexicanum.com/wiki/Elros
Coseflame - http://wh40k.lexicanum.com/wiki/Coseflame
Heterodyne - http://wh40k.lexicanum.com/wiki/Heterodyne
Balecaster - http://warhammer40k.wikia.com/wiki/Balecaster
Aryus One - http://darkreign40k.com/drjoomla/index.php/background/calixis-sector/1295-aryus-one-the-land-of-the-empty-hives
Fervious - http://warhammer40k.wikia.com/wiki/Fervious

Of course if you don't want to use one that's already detailed you could always use one of the little known ones.

Sisk - nothing found
Festus - nothing found
Penolpass - nothing found
Zillman's Domain - nothing found

I think the mission itself sounds pretty good for a starting group, and I'm sure you could have it in much greater detail for your players. My only suggestion is to have spare ideas written down in case your players go off track.
As a personal note, I always thought running a feudal world scenario would be close to running Call of Cthulhu Dark Ages. The only people with any power are the nobles, otherwise the citizens are afraid to go into the woods, afraid of the dark, very superstitious because of the horrors they have seen - very alien creatures that haunt the bogs and infest the forests, many unexplained phenomena that the peasants create stories about.
The Ecclesiarchy holds the most power, and even have relics, artefacts, and heretical books that are passed from abbey to abbey.

The preacher could even be part of a larger conspiracy that plans on using these psykers for methods that appropriate to whichever Ordos your acolytes will belong to. Though it sounds like your group will belong to Ordos Hereticus. Malleus is also another viable option, if the psychic powers are used to manifest warp beings, etc.

Looks like you've got most stuff covered fairly well and a solid plan for how to make it work. I don't really know what I would have to comment on. Is there anything in particular that you would want to us give comments on?

As a side note I could easily see that the heretics mentioned in the town are secretly following their pre-Imperial traditions, which may be fairly harmless or may be very sinister indeed, depending on what your story needs.

@Notivagent: Thank you for the links. I’ll take a look through those and borrow some ideas from them. I only know a little about Call of Cathulu but I was hoping to capture the horror element to this mission rather than the standard sci-fi feel.

@Gurkhal: My apologies, I wasn’t clear what kind of help I was looking for. I was really looking for a way to incorporate the noble type NPC into the storyline, but wasn’t sure if ‘the preacher is out to get him’ was good enough. Also, I’m a little low on ideas for specific scenes and confrontations with the PCs. I did have the idea of using the paranoia of the townsfolk towards outsiders as a way to cause conflict between them and the PCs. Also with secondary characters having alteria motives to not help them, but I’m a little low on ideas at the moment. I do like your idea of traditional beliefs though, so will definately incorporate that.

If you're more comfortable running CoC, I recommend sending your players to Dusk- as its virtually the same. An old haunted swamp/forest planet where the Veil is weak and the warp's influence can be felt heavy in the air.

Their technology level is also low, gunpowder and oil lamps- which can be attributed to frequent generator failures due to the conditions of the planet. Do you happen to own the Inquisitor's hand book? There's some information on Dusk there, and even an Origin should the constable player choose to actually come from Dusk.

In such a place, a feudal/death world- there could be a very viable power struggle between the Noble, who owns the bodies of the people and the land, and the Priest, who would "watch" their souls.

Edit- Agreed with everything's been said in the thread, you seem to have your story pretty set up straight. Have you ever watched sleepy hollow? Its pretty close to what your trying to do: Some people are being killed by an supernatural entity... Conspiracy abound when a pattern is found and nobles start getting knocked off... When it turns out someone was controlling it, that's when all hell breaks loose Hehe.

Thanks for the reply. I've just read about Dusk and it's crazy how similar that description is to what I envisaged. I'll definately be basing it on there now

If you want the preacher to be going after the local lord, who is protected from direct attack maybe he is trying to raise the townsfolk against him. Blaming the attacks on the faithless heretical practices of the lord (whether or not he actually is doing such things). His ultimate aim is to bring the lord down with the townsfolk a means to an end, with the possibility that the whole experience turns the townsfolk onto the 'right path'.

A classic 'doing bad things to get the right result' dilemma.