>players journey into Hell
>see enormous towers made of glass and steel
>a sky of choking black clouds, acid rains
>the devils use strange devices and ride iron beasts
>players start to piece together the bizarre truth
>Hell is actually a distant future of an alternate material plane
Could it work?
So Hell is our modern world? Hmm, that would explain all the invasions Hell commits to the material planes. The question then becomes why the heck are the material planes not nuked to oblivion?
>The demons project and possess their way into the material world to escape their own.
>Nuking it would defeat the point of the trad fantasy setting they escape to.
>Besides which there are already nuked worlds if they're in the mood for that.
The party discovers that they are possessed weekly by a group of four demons while a fifth antagonizes your possessed bodies by sending threats their way.