Ben Macintyre on Moscow's Agent Sonya

British historian Ben Macintyre's new book, "Agent Sonya: Moscow's Most Daring Wartime Spy," is the untold story of one of the Soviet Union's most successful operatives and of one of history's most successful female spies. Hiding in plain sight as a housewife in the English countryside during the Second World War, Ursula Burton was handling missions which would set the stage for the Cold War and enable the Soviet Union to build their own nuclear bomb.