Code Name Verity is told in two parts: in the first, Julie, a British spy captured by the Nazis in 1943 in France, writes the story of her friendship with Maddie and how both women became involved in the war effort. In the second part, Maddie, a pilot, keeps a diary of what happens after she and Julie crash-land in France.
Julie is captured in Ormaie (a fictional French city) in early October of 1943, when a member of the Gestapo sees her look the wrong way before crossing the street (which is a giveaway that Julie is British rather than French). The Gestapo, led by Hauptsturmführer von Linden, torture her for a few weeks and then show her pictures of the back of Maddie’s crashed plane. In exchange for her clothes, Julie gives the Nazis wireless code for each of the 11 wireless sets in the back of the plane. In exchange for the final code set, von Linden gives Julie paper and two weeks to write her story. She feels like a traitor.
Von Linden wants to know about the British war effort; he wants Julie to list types of aircraft in use and airfield locations, and he wants her to describe how the British have used technology like radar. Julie doesn’t know much of anything—her bosses have purposefully kept her in the dark—but she decides to write the story of how Maddie got into flying and share what she knows as she goes.
Maddie began flying in 1938, when she and a friend witnessed a plane crash in a field. The pilot turned out to be Dympna Wythenshawe, one of only a few female pilots and even fewer female flight instructors. With Dympna’s coaching and new programs to train pilots ahead of the coming war, Maddie got her pilot’s license. When Britain declared war on Germany, Maddie got a job working in radar. There, she met a woman named Queenie (Julie), a trilingual Scot who quickly became Maddie’s best friend. Queenie was gorgeous, silly, and extremely smart and cunning. Both women soon attracted the attention of a man Julie refers to as the Machiavellian English Intelligence Officer.
With Dympna’s help, Maddie transferred to a civilian organization, the Air Transport Auxiliary (ATA), and began ferrying airplanes and pilots around England. She and Queenie spent two years apart, exchanging letters and seeing each other on occasion (as when they visited Queenie’s favorite brother, Jamie, in the hospital). Maddie gradually became aware of the Special Duties airfield, where the Moon Squadron planes took off to head to France and meet up with the Resistance. Maddie sometimes ferried Queenie around—and she learned that Queenie wasn’t working as a translator. Queenie was working as a spy and an interrogator, charming Nazi spies into spilling their secrets.
After a particularly disastrous interrogation that left Queenie bruised and shaken, Special Duties decided to send her to France on a mission. When the pilot who was supposed to fly her there got in a car accident, Maddie agreed to fly her friend to Ormaie. But Maddie’s plane was shot at on the way, and Maddie made Queenie parachute out rather than risk her life with a landing. That’s how Julie ended up where she is now.
Interspersed throughout Julie’s story about Maddie are notes about day-to-day life at the Gestapo headquarters. Julie most often writes supervised by a woman named Anna Engel, who translates Julie’s account into German for von Linden. Julie is devastated when she sees photos of Maddie’s plane crash and learns that Maddie died.
At one point, to help the Nazis’ public relations issues, von Linden cleans Julie up and invites an American who creates pro-Nazi radio propaganda, Georgia Penn, to interview Julie. Penn insists she’s looking for “la verité”—the truth—but in Julie’s understanding, everything said in the interview is a lie.
Julie’s cell opens onto the interrogation room, so she has to hear and smell the Nazis torturing their captives—and when Julie finally breaks and screams for a French girl to lie, von Linden forces Julie to watch as they behead the girl with a guillotine in the courtyard. Julie knows where her story is going to end: she’s considered a security risk, so she’ll end up at a concentration camp as a specimen for experiments, per the orders of von Linden’s boss, a man named Ferber. Julie ends her account by writing over and over that she told the truth.
The novel then jumps back in time to a few weeks earlier, when Maddie landed in France. Maddie is writing in her pilot’s notebook like a diary. Maddie made Julie jump out of the plane after they were hit, since the plane was carrying 500 pounds of explosives intended to blow up the Ormaie Gestapo headquarters. Maddie successfully landed the plane, though she broke the plane’s tail, and was immediately picked up by the local Resistance group. There was initially some confusion, as they thought she was Verity—Julie’s code name. But Maddie’s code name is Kittyhawk. The Resistance stashed 11 old wireless sets in the back of Maddie’s plane, hid the explosives in a barn, and then blew the plane up to make it look like Maddie died.
Maddie spends a few days hiding in a Resistance family’s barn. She grows close to the farmer’s eldest daughter, Mitraillette, and Mitraillette’s little sister, Amélie. The girls’ older brother, Etienne, has joined the Nazis, which his family hates him for—but it provides good cover for the family’s Resistance involvement.
Soon, it becomes clear that Julie had been captured. Maddie spends most of her time sick with worry. However, the local Resistance leader, Paul, teaches Maddie to shoot a gun and make bombs. Soon, the family decides to stop hiding Maddie in the barn and give her the identity of Käthe Habicht, a cousin from Alsace. The Resistance makes several attempts to get Maddie out of France—one time with Jamie, who’s been flying planes for the Moon Squadron for a while and also crashed in France—but for various reasons, the attempts fail.
As this is happening, Paul contacts Georgia Penn. Penn is a double agent who has offered to go into the Nazis’ headquarters to try to find Julie—and to everyone’s surprise, she’s successful. Penn shares that Julie has been tortured, but when Penn dropped Julie’s code name (Verity) in conversation, Julie passed on coded information about the Gestapo headquarters. Julie also implied that she believes Engel is going to have a “crisis of conscience,” so the Resistance should reach out to her.
Maddie, as Käthe, is the one to contact Engel. Despite Maddie’s new persona, Engel immediately recognizes her as the Maddie from Julie’s account. She leaves a hidden message on Julie’s silk scarf for the Resistance. It reads that Julie will be transported with other prisoners to a concentration camp tomorrow.
The rescue does not go according to plan. Though the Resistance manages to save a couple prisoners, the Nazi guards shoot several and also kill Paul. When Julie, who’s about to be cruelly shot in the groin and elbows, realizes that Maddie is alive and among the Resistance fighters hidden all around her, she shouts, “Kiss me, Hardy!” (Admiral Lord Nelson’s alleged last words at the Battle of Trafalgar). Maddie knows what Julie is asking for—and she shoots and kills Julie before the Nazis can torture her friend. Later that night, Maddie, distraught, shares a meal with the rose-grower, the old woman who gives the local Resistance circuit its name: the Damask Circuit.
Days later, a bag of laundry arrives at the Thibaut farm containing Julie’s written account. Maddie reads it and takes note of the instructions underlined in red—Julie, with Engel’s help (Engel did all the underlining), has told them exactly how to blow up the Gestapo headquarters. It also becomes clear that Julie didn’t tell the Nazis anything of note; she made up wireless code, messed up airfield names, and never gave anyone’s real name, except for Maddie’s. Mostly, Julie’s account is the story of the women’s friendship.
While Maddie is in Ormaie not long after to pick up maps for the mission, Engel catches her and takes Maddie for a walk. They discuss Julie and her final days. Maddie finds that she likes Engel. She also comes face to face with von Linden, whom she considers her mortal enemy. Not long after this, the Resistance blows up the Gestapo headquarters.
When Maddie is briefly at the rose-grower’s villa to pick up a car, the rose-grower shows Maddie where she buried Julie and the other female prisoner shot during the rescue attempt in her rose garden—and Maddie realizes this woman is Julie’s great-aunt. That night, a Moon Squadron plane—piloted by Jamie—arrives to pick Maddie up. Jamie makes Maddie fly home, disturbed by her confession that she killed Julie.
Once home, Maddie undergoes an interview with the Machiavellian Intelligence Officer, whose real name Julie knew. Maddie doesn’t give his real name either. He insists that Maddie won’t get in trouble for killing her friend, and she’ll be able to keep her job as a pilot with the ATA. Maddie tells him everything, but she doesn’t mention Julie’s written account or her own—she doesn’t want it to end up filed away in London. Instead, she sends it with Jamie to take to his and Julie’s mother in Scotland, so she knows what happened to her daughter. Maddie also receives word that von Linden committed suicide.
The novel closes with a letter from Julie’s mother to Maddie, thanking her for sending the accounts. Julie’s mother assures Maddie that Maddie did the right thing, and she asks Maddie to visit. Maddie, as Julie’s best friend, will always be welcome.
