England, 1942. Liz Grainger lives a privileged life in Dover with her 5-year-old daughter; Matty Fireman works in a London factory. Both are recruited as secret agents by charismatic Col. Cad Cadogan.

Liz and Matty prepare for duty, and Liz says a painful goodbye to yer daughter. Under cover of night, the new agents fly to France.

Matty narrowly escapes detection. Meanwhile, Liz learns that her childhood friend, Claudine, has been forced to billet German Col. Krieger and his officers in her chateau.

Liz makes plans to return to London with vital information for Cad. Trapped between the Resistance and the Germans, Claudine faces a ghastly choice: become a double agent or be handed over to the Gestapo.

Liz's husband wants to know the truth about her wartime activities. When she comes clean, he's outraged. Back in France, Kit warns Matty to be more careful, and Claudine provides useful information to the Germans

Matty has been captured and Imprisoned, endangering the entire operation and the safety of its agents. Cad must send Liz to learn what is happening in France.

Matty's interrogation becomes increasingly brutal. Liz learns the awful truth about who betrayed her friend and mounts a dramatic rescue efort with Kit. Can they reach Matty in time?