A data brokerage firm accidentally punched a server cable through to an underground network that predates the internet by forty thousand years. Whatever built it is not happy about the connection. The party is a crisis team sent to sever the link before the things on the other end figure out how to route through it.
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.