The Precursor Vaults

A civilization predating all recorded history left sealed vaults across the world, all somehow still powered. The party discovers the activation code that opens them — and discovers every vault on the continent is connected, meant to be opened in sequence, and that opening them out of sequence has triggered the first stage of a countdown whose purpose the precursors did not explain in any language anyone can read.

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.