An explorer returns from the wilds outside the city of Aeol with a marvelous treasure that he claims he found in one of the uninhabited ancient ruins that dot the rest of the world of Ea where Aeol is located. While this was all he could carry bak this trip, he said the ruin he found was full of all sorts of other wonders—and might also hold clues to the persistent mystery of who built those ancient cities in the first place, and what happened to their long-vanished inhabitants. He approaches the PCs to accompany him back to the city, not just to loot its treasures, but to delve into its secrets and see what can be learned from what it holds.
Unfortunately, his true motives are different. A wandering mage did find an ancient wonder in the ruined city, and wanted to study its effects—but in order to do so, he needs human test subjects (well, intelligent test subjects, if not necessarily human), and he hired the explorer to bring them to him. There may still be treasures and secrets in the ancient ruins for the PCs to discover, but they're going to have to escape the trap that's been laid for them first.
