Even more than the CIA, the National Security Agency prides itself on its secrecy and its security. Headquartered behind an electrified triple barbed-wire fence at Fort Meade, Md., NSA is the agency that formulates U.S. codes and tries to crack enemy codes. Behind the barbed-wire curtain last week hummed an unaccustomed turmoil of alarm: two NSA employees had disappeared.
Bernon F. Mitchell, 31, and William H. Martin, 29, both mathematicians doing statistical code analysis at NSA, went off June 24 on vacation together as usual. Ever since they first met as naval communications technicians in Japan...