Mark Whitacre: The Spy Who Cried Help

The day before he tried to kill himself, Mark Whitacre told his groundkeeper to come late to work. Fortunately for Whitacre, Rusty Williams takes pride in being punctual. Arriving at the four-acre Whitacre estate in Moweaqua, Illinois, shortly after 7 a.m. on Aug. 9, Williams found his employer unconscious in his car in a garage filled with auto-exhaust fumes. Williams drove the car out of the garage and shook Whitacre awake. "I just thanked God when he coughed and started speaking," he recalls.

But the mystery remained last week even after Whitacre, 38, recovered in a Chicago hospital. Why would a...