One year ago, a group of adventurers went to explore a set of newly-uncovered ancient ruins outside your town and abruptly vanished. An earthquake soon undid any excavation, and everyone’s attention turned back to farming and herding and trading. Until today, when one of the heroes reappeared… Her words could have been written off as delusions or the fever dreams of some illness except for two things: one, the green orb she is clutching gives off the most palpable glow of arcane energy any of you has ever felt, and two, the appendage with which she is clutching it is a writhing green tentacle. A 5th-level adventure.