Last year I ran a horror film inspired scenario set in the 80s.
The background for the scenario is in the late 1600s, there is a group of cultists through Europe who worship some vague aspect of Nyarlothep. Through periodic human sacrifice. They're granted some super-human abilities (in 6th Edition terms, they had one stat at 19). Throughout the years they got arrogant, and sloppy, which lead them to be chased from Europe to the US, and spread through the US. in the 1800s, they had, again grown arrogant, again chased away, this time to a small town in South Carolina. where they continue their practices of human sacrifice.
By the time the PCs show up, they have started to get arrogant again, which leads them to getting sloppy in their behavior (giving the PCs a chance).
The scenario is set in 1985. The PCs have just graduated high school and are on their way from Ohio to Florida for one last hurrah. Borrowing one of their dad's old RVs. they head out on the road. The trip is cut short when, taking a backroad short cut, they run over a black-painted strip lined with nails that someone through across the road.
And thats where the scenario starts.
The townsfolk through set up the trap to lure in the PCs to be sacrifices. Once all four tires on the RV are blown, the PCs are in the middle of no where with very little chance of help.
After a few minutes of thinking about what to do, and consulting the map on where to go (the last town they saw was several hours (by car) behind them a old pick up truck shows up (heading in the same direction they came from). These overly friendly hillbillies quiet helpfully agree to drive some (or all) of them to the auto-shop a couple miles down the road (in the direction they were headed).
At this point I let the PCs sandbox it within the town full of weird and overly friendly townspeople (based on personalities from the Andy Griffith Show).
The NPCs plans are to treat the PCs are royalty (since they are going to be sacrificed to their god) as part of the ritual and and the NPCs to act completely contrary to their supposed small rural town christian facade. Everyone is overly helpful, never getting upset a the PCs actions).
The sheriff will even invite the PCs to have dinner with his family.
A couple events I through in include:
-The PCs finding a still alive, but completely skinned, cat in the street, yeowling in agony.
-The woman behind who runs the Bed and breakfast putting on a show of making sure the girls PCs virtues intact.
-The B&Bs rooms were obsessively cleaned to the point there that even under their beds were immaculate.
-The locale diner had some of the best food they have ever had in their lives.
-A gang of locale school kids (none older than 12) harassing the PCs including groping them (both the males and female) before running away taunting them.
-The older kids are down at the pond, lots of drugs and sex going around. Clearly loud heavy metal music. None of the adults seem to care.
-Library having a lot of weird books interspersed with the standard library books. Things that no small rural community would normally have. (use your imagination).
-At the dinner with the Sheriff's house, the 18-year old 19 APP daughter of the sheriff and his wife tries to get one (or more) of the PCs upstairs. The parents clearly know whats going on and don't seem to care. Anyone willing to be pulled in should be shocked by how far the girl is willing to take things. Literally make the PCs uncomfortable as possible.
-Anything the PCs do are met with amusement from the NPCs. Even to the point where they terrorized a small child (which they did in my runthrough) in front of the parents.
-The deputies (all 19 CON) are keeping a close eye on the PCs. The PCs should have a chance of spotting their being stalked by the police, but nothing overt. cop cars driving by often.
-The local reverend is 'specially creepy. a exploration of his home finds souvenirs (old drivers license, pictures of previous victims, jewelry, even preserved pieces of the previous victims).
The important thing to keep in mind is that everyone in town is overly friendly and helpful, regardless of how far the PCs push it. PCs treated as royalty. A very shallow facade of small town christian fundamentalism (though not hell and brimstone). Kids running around out of control. Scratch the surface and it's all bad.
After one day (and night in town), the townfolks were going to capture the PCs (as unharmed as possible), take them to the fairgrounds (which the town has been preparing while the PCs are in town for the "Town Fair"), the characters are dragged there, sacrificed, and their bodies eaten by everyone in town, to consume their power and continue their pact to their evil god.