So he built a prototype pair of magical spectacles and went down to his local inn. When he put them on it was pretty immense; the majority of the pub appeared to be horned demons. He was expecting this; the spectacles just made them appear this way if they had behaved badly. He knew it would take a lot of work until it would only single out people who had just done serious crimes;for now he took them off and left them on the counter whilst he had a beer. A big mistake as it turned out.
A rather elderly lieutenant from the Strafcullen First Firebow regiment who was near retirement and who now needed to wear spectacles put them on, and thinking himself to be suddenly plunged into the depths of Hell grabbed his army-issued Firebow and opened fire at the nearest person, who happened to be a member of a criminal gang of highwaymen who never normally caused trouble in the village as they lived there and it didn't make any sense to "foul their own nest." Seeing one of their own pinned through the chest with a blazing arrow from a Firebow, and without provocation to boot, they drew their blades intent on killing the bowman on the spot. The bowman was not alone though, he was with a few of his fellow officers, not the *red tab* staff type but tough fighters who were veterans of several campaigns. The highwaymen had greater numbers, but the veterans cancelled this out by their military combat skills.
With things equally matched the entire pub clientle started fighting, either to side with their friends, get away or just for the hell of it. Swords and daggers pierced chests and torsos, clubs and chair legs cracked against heads and arms and in trying to get his spectacles back the wizard was run through by the maddened lieutenant who thought he was an attacking demon. The pub ended up burning down from a firebow arrow but miraculously the spectacles survived.
The spectacles reflect back evil by making those who have done something evil look like demons;sadly, they have not been calibribrated properly and cannot discriminate between serious criminals and those who are only minor lawbreakers, so most people other then babies and small children and very well behaved people are portrayed as demons through the spectacles. If they were ever refined properly however so only certainly serious criminals were targeted they would be a very effective crime fighting tool, at least for finding the criminals.
I'm in Hell!
One of the PCs has put these on not knowing of what it does and finds himself or herself suddenly surrounded by demons.
The PCs are to swap these secretly with the spectacles of a high-ranking courtier so he will flip out and discredit himself at court. They are being paid to do this by a rival courtier.
Bring them in
They have been properly made ready and are being taken to a factory to make more of them, but organized crime is trying to capture and destroy them before they can be mass-produced and the PCs must get them to their destination safely.
Additional Ideas (1)
I am Justice:
A vigiliante wearing a strange set of spectacles has plunged criminal and innocent alike into terror as his zealotry for the forces of good endangers all.