Code Name: Emerald

Col. Brausch informs Hoffman that there is an agent in British Intelligence codenamed Emerald. They task this double agent, Lang, with delivering an Overlord to the Nazis and exploiting the information he might obtain. The pressure is high after six failed attempts to capture an Overlord.

Lang passes on fake details of a D-Day rehearsal to the Nazis, including a decoy ship carrying Overlorders. Meanwhile Allied command decides to hold a real D-Day rehearsal anyway, hoping to catch the Germans out. British intelligence forges a false medical condition in Wheeler’s records to keep him from being tortured, and Lang secures Wheeler’s actual medical file to maintain the ruse.

Lang parachutes into France and is met by Henri, who drives him to Paris. He reports to Ritter in Paris and then meets Claire Jouvet, who will secretly relay his reports to the British. Lang and Claire begin a dangerous collaboration that blends espionage with a growing romance.

In Paris, Lang is incorporated into the interrogation plan by Ritter, Brausch, and Hoffman. He pretends to be a fellow American prisoner and starts befriending Wheeler to coax information about the D-Day plan. Wheeler endures disorientation and confinement as part of the Nazi interrogation regime.

Lang evades Gestapo tail to meet Claire in a Paris Metro carriage. Claire agrees to relay his reports to a Belgian Resistance radio hidden near a church altar and passes information back to Lang. They pretend to be lovers, and their bond deepens under constant risk of discovery.

Ritter investigates Duchelle, Claire’s contact, and uncovers a link to Claire’s Resistance activity. He also learns Claire’s ancestry includes Jewish blood, a detail the Nazis treat as a dangerous liability. This surveillance heightens the tension between the German officers and Lang.

Lang persuades Wheeler to talk and reveals information that only an Overlord would know. He confirms the invasion will be Normandy, despite Wheeler initially thinking Calais is the target. Lang provides Wheeler with precise guidance on what to reveal to the Nazis.

Hoffman meets Callaghan and learns that Wheeler’s perceived heart condition was fabricated. Ritter shows Wheeler the restaurant photograph that reveals Lang’s identity as a prisoner, leaving Wheeler to consider the torture that awaits.

Lang secretly meets Brausch in a church, where Brausch reveals a mutual ally in Macklin and warns that betrayers are dangerous. This conversation clarifies Lang’s precarious position and the scope of the Nazi-British chess game. The two men acknowledge the risks and the stakes.

During a country picnic, Claire shoots Hoffman when his plan to derail the rescue is exposed. The chauffeur is also shot, and Claire drives Lang toward the airfield for the escape of Wheeler. The act marks a turning point that shifts the balance of power in Lang’s favor.

Claire forges Hoffman’s signature and a forged document is read aloud by Brausch. Lang claims Hoffman’s orders to move Wheeler to Calais, effectively placing him in charge of the mission. Ritter’s authority is undermined as Lang asserts control.

Lang and Braush move Wheeler toward Calais as Ritter alerts others. Henri’s fish van provides cover as they head to the airfield, where a rescue plane awaits. The pace quickens as time runs out before German forces close in.

The rescue plane takes off with Wheeler aboard, followed by Lang, Brausch, Claire, and Henri. Claire reunites with her son; they all reach the airfield and escape into England as German pursuit narrows. The passengers share a kiss and relief washes over them.

The film concludes with brief real footage and commentary on the D-Day landings on June 6, 1944. The action, deception, and sacrifices culminate in the Allied invasion. The timeline closes with real historical context.