That was odd. Even more peculiar, it looked as if they would have to call in a materials expert to identify this substance. It was not jade, not glass, not pottery of any kind. It retained its warmth long after sunset—and nights were often brutally cold on this high, arid plain. And it looked strange. Deceptive to the eye. Slippery. From a distance, it seemed almost to shrink—to disappear, if you stood a few yards outside the dig, in a stitch of air and sand.

On the fourth day after his discovery Delmonico was confined to his tent, vomiting every twenty or thirty minutes into a half-gallon mason jar while a wind storm battered the canvas and turned the air to chalk. He had come down with the flu, everyone said. Or common dysentery—he wouldn’t be the first. Delmonico accepted this diagnosis and resigned himself to it.

Then the sores appeared on his hands. The skin blackened and peeled away from his fingers, and the bandages he applied turned yellow with suppuration. Blood appeared in his stools.

His faculty supervisor drove him to Ankara, where an emergency room physician named Celal diagnosed radiation sickness. Celal filed a report with his chief of staff; the chief of staff notified an official of the Ministry of Public Health. The doctor was not surprised, given all this, when the delirious young American was taken from the ward by a military escort and driven into the night. It was a mystery, Celal thought. But there were always mysteries. The world was a mystery.

Delmonico died in a closed ward of a U.S. Air Force medical complex a week later. His companions from the dig were quarantined separately. The two postgrads who had labored over the jade fragment lived another day and a half before dying within an hour of each other.

The rest of the expedition were treated and released. Each was asked to sign a paper acknowledging that the events they had witnessed were classified and that divulging those events to anyone for any reason would be punishable pursuant to the Official Secrets Act. Shaken and at a loss to make any sense of what had happened, all fourteen surviving Americans agreed to sign.