I am working on an adventure where all the guards turn on the townfolk. PC's have to step in and protect the civilians/take down the guards. I am thinking that the guards have either been poisoned, diseased, or are somehow being dominated by a creature. Any suggestions on the best way to do this?
Party will be 5th level.
Trying to come up with 2 encounters. First fight/disable the guards.
Second, determine what happened and deal with it.
Campaign is set in Eberron. Adventure occurs on Lightning Rail train speeding along. All of a sudden, the Deneith guards on the train go insane and start attacking the passengers. After the PC's deal with them, they have get to the engine and stop the train before it wrecks.
I just don't know what is causing all the mayhem.
I'd go with a dominating monster. It's a more tangible cause than trying to diagnose some mental disorder. Then you;d have to figure out how they got it, what its MO is, etc. Make it a monster and your work is half done for you. Why did it do it? It's a monster! Raaaaarrrrrr! Seriously, eberron shoul dhave plenty of mind-altering critters to play with.
I'd have to agree with Shiftkitty on this one.
Insanity wouldn't really fit the bill, because the cause has to be from some driving force. Maybe combine the two. Maybe the monster drives the hearts of the guards insane and makes them attack their own people- turning them into monsters themselves (not literally).
Does that sound good to you?
Presence of an artifact or a gate, maybe? If the town guard were all (or mostly all) present to guard something in the recent past, they could have been affected (infected?). The television show Angel had a 'demon shroud', kind of an anti-shroud of Turin that had a similar effect.
@ Shiftkitty, is your sig a general statement on mortality, or something more...specific?
@ Shiftkitty, is your sig a general statement on mortality, or something more...specific?
@ Mynameisjake:
I just laugh at your sig every time I see it! 
"NO! This! Is! WIZSPACE!!!"
It kinda reminds me of: "This! Is! SPARTA!!!"
Thanks. If we ever get spoiler blocks back, I'm going to embed little screen captures from that scene into my sig.
Okay, here is what I am thinking. Someone (maybe the druids that hate technology?) has somehow infested the engine compartment with an Ambush Vine plant. This vine has pretty much overgrown the backend of the engine cart. This variety of vine has a flower that has a poison scent attack which drives people insane. So, the guards have been overwhelmed by the flowers.
The PC's have to get past the guards, then hack their way through the vine (or go out and across the top of the moving train with occassional vine tentacle attacks) to get to the controls to stop the speeding train.
Any glaring holes in this idea? Or any better suggestions?
Thanks
Only question is - why the guards and nobody else? You'd think it'd be more like people at the front of the train attacking those at the back of the train, or something.
Maybe the cook for the troops is in on it and harvested the flowers to put into the soldier's crap.
Some soldier might not be dominated some might.
The crew's quarter's are in the front of the train. So it really is the people at the front that are affected. I was going to have a Cannith magewright that works on the train barracade himself in his room and call for help. Maybe he befriended the party earlier in the journey.
There were plant grafts in 3rd edition. I may go with something like that, but the grafts are controlling the guard that it is grafted to.
@ Shiftkitty, is your sig a general statement on mortality, or something more...specific?
Actually, it was a possible answer from an old Dragon Magazine questionnaire called "U 2 CAN EARN BIG BUX!". Each question was accompanied by a multiple-choice answer clearly aimed at various classes. One question was a complete the statement: "If there's anything I hate, it's..." and the various answers included things like "orcs in spandex", etc. I chose the Barbarian's answer. I asked for permission to reprint the quiz on this site, but was denied. Too bad. It was a funny quiz!