Occupied Paris, 1942. In the dark, treacherous city, the German occupying forces are everywhere – and so are French resistance fighters, working secretly to defeat Hitler. Just before he dies, a man being chased by the Gestapo hands off a strange-looking document to the unsuspecting novelist Paul Ricard. Drawn deeper and deeper into anti-German efforts, Ricard travels deep into enemy territory and along the escape routes of underground resistance safe houses, spying on Nazi manoeuvres. And when he meets the mysterious and beautiful Leila, a professional spy, they begin to work together to get crucial information out of France and into the hands of the Allied forces in London.