In 1943, America thought it had rounded up all the German spies on its soil. Now Germany's greatest weapon - a woman with special talents, both for tradecraft and for death - is headed home with critical information about the still-developing atomic bomb, and the Aliies chief hope for stopping her is a British agent with agendas of his own. Originally recruited into MI5 to pose as a double agent, he's been telling Germans that he'd do anything to free his wife, a prisoneer of a Polish concentration camp. This happens to be true. The question is: how much would he really do to set her free? Where are his loyalties exactly?

As the two spies play cat-and-mouse across three countries, the ambiguities deepen, each figure showing new sides, each action providing new twists, until at last both agents are swept into a series of climaxes as breathtakingly unpredictable as they are inevitable.