The legendary black-market auction The Collection sells one item per year. This year's item is an intact map to the pre-Collapse vault containing the source code for reality itself, written in a language predating human civilization. Everyone with power is in the room. The party is there to steal the map before the auction closes.
Play this campaign right now with an AI Dungeon Master that narrates the world, voices every NPC, remembers your whole story, and asks for the rolls — solo or with friends.