There is an island, on which can be found a gigantic carnival, run by devils. Infernal sea creatures surround the island and attempting to land anywhere other than the docks would require a full on military assault. The devils who run the place will allow anyone entry for three days, in return for their soul. Payment isn’t required up front, but you have to sign a contract and are expected to turn it over at the end of the period.

The carnival itself is truly a magnificent affair; extraordinary rides, sumptuous all-you-can-eat buffets, magnificently comfy beds, even a brothel of shapechanging succubi, who can fulfil any fantasy you might have. Not only that, the island itself is magical and will almost immediately heal any illnesses or injuries, short of regrowing entire limbs. The majority of people who visit are usually facing imminent death and looking for one last fling.

At the end of the three days, some folk do just turn themselves over, though most either accidentally or deliberately lose track of time and simple carry on their revels until a pair of devils find them and collect payment. However, some people realise that signing over their soul was maybe not the greatest idea ever and try to run. The longer they stay past their allotted time, the more the carnival’s glamour fades; those who make it 24 hours past the deadline (not that many) quickly find the island is moving into creepy carnival territory. The only advantage this brings is that they start to see the service areas and such like, where they can more easily hide. Very few make it more than three days once their ticket is up, though it is not completely unknown.

Plot hooks:

1) For a light hearted action campaign, someone is unhappy with the operation (maybe a loved one lost their soul there) and hires the PCs as part of an all out assault on the island. This would involve lots of crazy set pieces, fighting devils on rollercoasters and whatnot.

2) For a more sinister campaign, the PCs are hired to exfiltrate someone who has gone in and is already past their “expiry date”. In order to get in themselves, the PCs have to sign away their own souls, so they’re going to need to find a way off the island for them and their target.

3) Possibly word is getting around that selling your soul isn’t worth it, so the devils offer a week of free entry for everyone. Of course, it’s not really free… the “sell your soul” part has just been hidden in the small print of a liability waiver for the crazier rides. All hell breaks loose (ha!) when a carnival full of tourists realises they’ve been duped and the PCs must find an escape route during the ensuing chaos.