Better. Than. Fiction.

The Soviets took notice. Not long after his initial discoveries, Mr. Frey said, he was invited by the Soviet Academy of Sciences to visit and lecture. Toward the end, in a surprise, he was taken outside Moscow to a military base surrounded by armed guards and barbed-wire fences.

“They had me visiting the various labs and discussing the problems,” including the neural impacts of microwaves, Mr. Frey recalled. “I got an inside look at their classified program.”

Moscow was so intrigued by the prospect of mind control that it adopted a special terminology for the overall class of envisioned arms, calling them psychophysical and psychotronic.

Soviet research on microwaves for “internal sound perception,” the Defense Intelligence Agency warned in 1976, showed great promise for “disrupting the behavior patterns of military or diplomatic personnel.”

Furtively, globally, the threat grew.

The National Security Agency gave Mark S. Zaid, a Washington lawyer who routinely gets security clearances to discuss classified matters, a statement on how a foreign power built a weapon “designed to bathe a target’s living quarters in microwaves, causing numerous physical effects, including a damaged nervous system.”

Mr. Zaid said a N.S.A. client of his who traveled there watched in disbelief as his nervous system later unraveled, starting with control of his fingers.