Players, plans, and betrayals: as WWII proceeded, Soviet and British intelligence operatives and American private interests sought to infiltrate and influence American operations.

May 1941, New York City. The 33-year-old woman stepped out of the office building lobby onto Broadway. It was late in the evening. "The street as usual at that hour was deserted," she would later recall, "except for two young men, one on either side of the next corner, where they could effectively block my progress up Broadway. My heart felt as if it had stopped. This was it!"

With terror, she remembered that she was carrying, carefully wrapped in a newspaper, a package of documents that could not be allowed to fall into the wrong hands. Affecting as much composure as she could muster, she calmly walked into a candy store, intending to use the pay phone to warn ...