In London's King George's Park one sultry evening last week, a pasty-faced young Briton kept an appointment with Pavel Kuznetsov, ferret-faced second secretary of the Soviet Embassy to Britain. The young fellow was William Martin Marshall, 24, a $21-a-week radio operator employed by the Foreign Office to transmit clear and coded messages to British missions abroad. Once a clerk in Britain's Moscow Embassy, he had been meeting Communist Kuznetsov clandestinely for several months.
Engrossed in their conversation, neither Briton nor Russian noticed three burly eavesdroppers lurking near the park's deserted bandstand. But as Marshall turned to go, the three men...