For a time, Hiskey worked at the Tennessee Valley Authority and the University of Chicago Metallurgical Laboratory, part of the Manhattan Project.
The message contained information reporting that Bernard Schuster, member of the CPUSA secret apparatus, working for Soviet intelligence, had traveled to Chicago on the KGB's instructions.
On 28 April 1944, Army counter-intelligence (G-2) observed a meeting between Clarence Hiskey and Soviet Military Intelligence (GRU) officer Arthur Adams.
While en route, Army counter-intelligence officers secretly searched Hiskey's luggage and found seven pages of classified notes taken from the Chicago Metallurgical Lab.
In testimony before HUAC and Senate Internal Security Subcommittee, Hiskey repeatedly refused to answer questions about his Communist associations and espionage, and in 1950, he was cited for contempt of Congress.