In 1942, London is in the middle of the Blitz. The city is blacked out and bombs shatter the night. Charlotte Gray is an ordinary woman who travels from Scotland to London to see how she can help. At a party, she meets Peter, a battle-weary RAF pilot on leave, and they fall in love. But the affair is abruptly halted when Peter is called back into service and his plane is shot down over France. If he is alive, he is probably hiding, sheltered by the French Resistance. Soon, Charlotte is also on her way to France, for like many women fluent in French, she has been recruited as a secret agent, working to support the Resistance. She could have asked for an assignment at home, but instead she jettisons fear, accepting a dangerous mission behind enemy lines, keeping secret her personal mission to find her missing lover. In a world where secrecy is all around, she discovers that she can only trust what is in her heart.