“ Within a kingdom the prince or princess has died or been killed and the Queen has been driven half-insane with grief.What if one of the PC's was mistaken for the dead prince or princess and not allowed to leave? There would be advantages in accepting the role, but would it be worth it?”
“ What if you send the players in a dungeon that was already raided? Maybe you could have traps that are already set off, or the corpses of monsters etc.”
“ The religion believes in reincarnation, but that you will be reborn in the past. People of today are those re-born of tomorrow, with some discarded as trash. The most pure will be eventually reborn in the mythical paradise-like past, where people lived for hundreds, or maybe even thousands of years.
This goes nicely with beliefs into foresight (you know a little about the future because you have been there), but also to many complaints of how things are going always from bad to worse.”