Born in 1904 and raised in Zurich, Switzerland, by upright, pious, and wealthy American Quaker parents, Noel Field was brought up to be a fervent – but, alas, eternally naive – believer in peace and equality. After his father’s death in 1921, Noel, his two siblings, and their mother relocated to the U.S., where Noel attended Harvard and then joined the State Department, an idealistic and unworldly young man determined to use his position to remedy the world’s cruelties and inequities.

In Washington, D.C., Field and his Swiss wife, Herta – whom he had known since he was nine years old – lived in a black neighborhood and, appalled by the racism they observed, took part in anti-segregation protests.

Then there was the case of Sacco and Vanzetti, two Italian immigrants who were convicted of murder in 1921 and executed in 1927. The case made international headlines, resulted in the formation of defense committees around the world, and led to riots and vandalism. All this activity on behalf of the two defendants was believed at the time to be spontaneous; in fact it was all orchestrated by a U.S.-based Soviet agent, Willi Münzenberg, who saw the case as a golden opportunity to destroy “the myth of America” and thus make the U.S. fertile ground for Communism. Millions fell into his trap. One of them was Field, whom Kati Marton, in her recent biography of him, describes as “an ideal target” for Münzenberg’s machinations.

Disillusioned by his own country, Field began to read the works of Marx, Lenin, and the American Communist John Reed. He subscribed to the Daily Worker. Soon he was a “secret radical.” Bookish, sheltered, and utopian-minded as he was, he was easily drawn to the Communist dream of a workers’ paradise. The fact that he’d never set foot in the Soviet Union helped. “His exposure to Stalin’s Russia,” notes Marton, “came entirely from Moscow’s propaganda.” The Daily Worker‘s glorious descriptions of Bolshevik life – which he took entirely at face value – contrasted dramatically with America’s economic inequality and racism, which he saw firsthand.

Marton cites another factor in his attraction to Moscow: brought up in a starchy milieu (part WASP-y, part Swiss) without much in the way of human intimacy, the “stiffly self-conscious Noel” was deeply moved by the feeling of warm solidarity he experienced at a 1929 gathering of Communist laborers in New York City. “For once,” he wrote, “I felt myself a ‘comrade’ among that enthusiastic workers’ audience.”

It would take five more years before Noel Field fully shifted his allegiance. But he was already on the path to treason.