World War I has almost come to an end, but for a young Minneapolis railway employee and amateur actor named Paul Peachy, whose marriage has become one-sided, it’s time to enlist.  Shipped off to France, Peachy realizes how out of his depth he is—and never more so than when he is captured.  Risking everything, Peachy—who as a child of immigrants speaks German—makes the reckless decision to impersonate one of the enemy’s most famous spies.

As the urbane and accomplished spy Harry Stroller, Peachy enters a world he never even knew existed—a world of sumptuous living, world-weary men and available women. But when one of those women—Annie Breton, a young, wary and beautiful courtesan—turns out to be more than she seems, both Peachy’s and Annie’s lives are transformed forever.