Warsaw 1938. French military attache Colonel Jean-Francois Mercier is also a spy on a mission, one which takes him undercover to Czechoslovakia on the trail of the elusive Chaika, a man who can lead him into the heart of the Nazi war machine. Back in Warsaw, his erstwhile mistress Anna Skarbek is devastated by news of her ex-lover and political refugee and journalist Max Mostov. Heartbroken, she flees to Spain on a League of Nations mission of mercy. As the Nazi storm clouds gather over Europe, dashing Polish Colonel Anton Pakulski undertakes his own mission, a mission that goes to the heart of protecting the very future of Poland itself.