1944, the Cote d'Azur. Artist Marguerite Segal is recruited by British Intelligence into befriending Etienne Valade, a local priest. Her mission is to persuade him to pass on information from the high-ranking German officers who attend his church: evidence of their war crimes. Connected by a passion for art, Marguerite and Etienne soon fall in love, but their association increasingly puts her at danger of violent reprisals. With his church frequented by Nazis, Etienne is a suspected collaborator, and distrust is high. And Marguerite is keeping her own secret too. Like the Jews whose identity cards she forges to hide them from the Third Reich, she is hiding behind a false name, her true identity and past known only to her closest friend. Marguerite must get hold of the documents that will condemn the German officers but, in a world where everything is at stake, can she truly trust anyone -- even the man she loves?