As Ruth walked to her next class, down the gap between Wilkinson Hall and Edison Labs, there was a commotion behind her in the quad: people running, a siren, an ambulance. She decided she didn't have time to go back and see what it was about.

After class, someone who was waiting for Thermo 314 said, "You wouldn't believe what happened in the quad, less than a hour ago. Some female student was walking stark naked through the quad. Not a stitch on. Of course, a bunch of guys started whooping and yelling and pointing, and that poor girl looked like she'd die of shame, trying to cover herself with...