I have this idea I want to develop into a full adventure and I thought I'd share here to see what you think.

Its an urban adventure, where the PCs are in a given town where a Witch-hunter has arrived. Some hiddeous heresy has been detected and the Witch-hunter is bound to find a culprti. The twist is that the evidence found seems to point in the PCs direction. I imagine an investigation track for the witch hunter and PCs, with several event tracks. The witch hunter advancing would be based on his investigation being guided towards the PCs and the PCs advance would be fiding evidence of the consiracy behind the setup. Events would start as brushes with the Witch-hunter or his cronies, to chase sequences through the streets of the town.

This is just my first thoughts, I'll start writing soon the full details on it. Any ideas will be apprecited. Also if anyone has any thoughts on possible stats for a particularly strong Witch-hunter that would be awesome.

Witch Hunters often travel with a few underlings, and I think they'll give you a lot of mileage with this sort of adventure. Former soldiers and bounty hunters could provide extra muscle, while a ranting zealot might be a good way to remind the entire party of why they're in this line of work. The group might all travel in a black coach with skulls and gothic crosses painted on the side, and covered in those sacred wax-sealed parchment ribbons.

The PCs could be introduced to (or become aware of) the Witch Hunter after an encounter with one of its underlings. That might be a good way to build up suspense about meeting such an important and intimidating figure. In a good horror movie, you don't want to see the monster right away. The minions might even be relaxing in a tavern, or specifically planted in the town to gather information.

Maybe the Witch Hunter has been deceived about the nature of their prey? A merchant who wants to eliminate his competition might have made up lies and accusations of witchcraft about someone else. If the PCs pick up that one piece of information that the Witch Hunter lacks, they might find themselves standing between the Witch Hunter and an innocent man, because it's the right and just thing to do.

That would give you a good reason for the Witch Hunter to turn their attention to the PCs, and start hunting them. It wouldn't be easy to convince a Witch Hunter of your innocence, but this sets up a situation where the climax of the story is a social encounter, or a combat scene with lots of talkin'. Maybe the PCs are chased into a tower or some other building, and have to fight off the cronies while shouting at the Witch Hunter, trying to reason with him or her, presenting evidence of their good intentions and logic while parrying and retreating up stairs.

You could build towards a trial where those social skills are going to come in really handy. I know Witch Hunters don't have to go through trials, but perhaps the PC's have connections that force the issue.

The PC's could be framed by cultists they've encountered. Have they let anyone escape?

If you want to get really gruesome, have one of the PC's captured and 'convinced' to reveal where the others are.

I' use this story to really drag the PC's over the coals and make them grateful that they've escaped with their lives intact, let alone their bodies. I really don't think that PC's fear Witch Hunters enough - the insipid ones in Paths of the Damned did a job on that front.

I always thought an interesting, witch hunter-centric tale might involve someone impersonating a witch hunter. Perhaps an evil-doer seeking to gain the respect, (albeit out of fear), commoners afford to those in the position.

Here's one possibility: a powerful Chaos cultist, (maybe a follower of Tzeentch?), manages to somehow kill a witch hunter and then usurp his identity, possibly in order to raise himself above suspicion, or maybe, to infiltrate the Order of Sigmar to weaken it from "the inside". The PCs could meet the cultist and get an initial feeling that something is "off". From there they could work to uncover the truth. I haven't thought about it much, save the general concept, so I don't really know where it would go from there.

(As a side-note, the other ideas posted prior to this one are very interesting. I like the idea of a trial where the PCs attempt to prove their innocence very much.)

I was also thinking of adding a third faction to the adventure, which would be the townsfolk themselves. I'm thinking they're growing weary and tension is running high, so if something is not done quickly, some torches will be lit up and pitchforks sharpened.

The party did have some cultists escape from their An Eye for an Eye story, but I don't feel like using them for this.

Current shape of the story is :

Party (based in Übersreik) returns home from the Manor, only to find very few people on the streets and much discomfort among the townsfolk. A series of gruesome events has ocurred throughout the party's absence and a witch-hunter has been called. The gruesome events stopped when the PCs arrived back in town, which will make them suspects to the events. First encounter will be with the underlings of the witch hunter, poking for clues (maybe they're posing as regular people to collect info or something). After the PCs have been given fair warning, the Witch-hunter closes the city gates, detrmined to find the blasphemy that dwells in the city. Investigation track will be set up with 3 parties in play:

1) Witch-hunter being misled by the cult / culprit towards the PCs

2) PCs finding out what really happened and who's to blame for it

3) Townsfolk grow weary of the situation and will become ever more violent and fanatic

I liked the idea about a merchant taking care of his opposition, so the real deal behind this all might be just that. The merchant (trying to brush off the atention) faked some Chaos ritualistic symbols (as Übersreik may have already gained knowledge from the events in Eye for an Eye). He did not expect things to grow so much and have a witch-hunter come to poke around, so wanting to get a scapegoat, points his finger to the PCs.

Great ideas so far, thanks to everyone for helping !

One of the published old school adventures had something pretty much exactly like this. Players were working with one church faction and wind up on trial for heresy by one of the other factions - being a secret plot by a chaos cult. I recall great chases through the streets from angry mobs and the trial that was a total kangaroo court frame-up with the players having to find proof of their innocence by finding the cults lair, etc. It was great... and I think it was part of the Enemies Within, but the name escapes me.