The first experiment by UX, in September 1981, was an accidental one. A Parisian middle schooler named Andrei was trying to impress a couple of older classmates, boasting that he and his friend Peter often snuck into places and were about to hit the Pantheon, an enormous former church that towers over the fifth arrondissement. Andrei got in so deep with his boast that to save face he had to follow through—with his new friends in tow. Like Claudia and Jamie in that famous children’s book From the Mixed-Up Files of Mrs. Basil E. Frankweiler, they hid out inside the building until it closed. Their nocturnal occupation turned out to be shockingly easy—they encountered no guards or alarms—and the experience electrified them. They thought: What else could we do?