The Rose Code
(Review, Recap & Full Summary)

The one-paragraph version of this: Three women (Beth, Osla, Mab) work on various aspects of codebreaking in Bletchley Park ("BP") during WWII. Beth learns there is a traitor at BP, but she gets hauled off to an asylum so that she can't report it. The womens' friendship also splinters at the end due to Beth not warning the others (because they take an oath of secrecy) about a raid that kills Mab's husband and child. Years later, Beth calls upon the other women for help to get her out before she's scheduled for a lobotomy. Together, and by calling in a bunch of former BP cryptographers as reinforcements, they get Beth out and decode the messages (the titular Rose Code) needed to identify and arrest the traitor.

In 1947, years after WWII, two women are contacted by a third woman, Beth Finch, who has been institutionalized in the Clockwell Sanitarium. Beth says she knows they hate her, but she needs their help. She claims a traitor set her up to declared crazy when she discovered proof of their treason. She asks them to come rescue her.

Back in 1940, Osla Kendall, 18, and Mab Churt, 21, are women who get recruited to work at Bletchley Park ("BP") at the Government Code & Cypher School. Collectively, they work on decoding German communications that have been encrypted with variations of a cipher device called the Enigma machine. Their work is highly secretive and revealing anything is considered treason.

Osla is an upper-class debutante, who starts seeing Prince Philip of Greece just before he ships off to war and she goes to BP. Mab comes from humble means, where she lives with her mother and much younger sister, Lucy, 4. At BP, Osla starts off doing secretarial work, but moves into translating German. Mab works in the decoding room (where they punch in messages to be decoded) and later works on running machines that test out settings to decode messages, called bombe machines.

Osla and Mab are billeted at the house of the Finches, where they meet Beth, 26, who lives with her parents. Beth soon gets recruited into BP to work with Dilly Knox's team of female cryptographers, doing extremely challenging decryption work. The three women bond over books and start a literary society, which they name the Mad Hatters Tea Party. Eventually, Osla and Mab help Beth to stand up to her overbearing and manipulative mother, and the three move into a flat together.

As time passes, Beth eventually gets involved with a man named Harry Zerb, who is legally married but he and his wife are only together for the sake of the child. Osla continues to see Philip, but she's told to break things off with him due to his Nazi familial connections. Soon after, there's rumors of Philip and Princess Elizabeth being romantically linked. One night when she is in London, Osla ends up in the midst of an air raid, and she is helped by a man who gives her his overcoat. She later finds the name "J. P. E. C. Cornwell" in the coat's lapel. Meanwhile, Mab meets and marries a good and loving man, Francis Gray. She's also able to reveal to him that Lucy is actually her daughter, not her sister, and he is supportive.

In November 1942, Mab and Francis are set to move to Coventry with Lucy, and Osla will be visiting, too, to help with Lucy. Beth deciphers a message about an upcoming air raid in Coventry, but does not say anything as it's against the rules to share details of their work. When the sirens go off, Osla accidentally lets go of Lucy's hand and she runs off. As soon as Francis finds Lucy, a bomb falls before they can make it to a shelter, and both Francis are Lucy are killed.

Mab blames Osla for their deaths, fracturing their friendship, and Mab drinks excessively following Francis's death. Around the same time, Dilly, Beth's mentor and supervisor, dies of cancer. Beth sees that Dilly's last project was trying to crack a Soviet Enigma code, and she's determined to finish deciphering it.

By June 1944, the tides of the war have turned, and the Invasion of Normandy is planned. Beth finally cracks the Soviet cipher (which she nicknames the Rose Code based on it's complicated structure), only to learn from it that there was a traitor in their midst. However, before she can report her findings, Beth is denounced by someone as having broken down mentally and is taken to the Clockwell Sanitarium. Osla and Mab have also just learned that Beth knew about the Coventry raid and in their anger and feelings of betrayal, they fail to defend Beth vigorously when questioned about her. Beth is locked up for the next three and a half years.

By November 1947, Beth manages to get the messages asking for help out to Osla and Mab. Osla is now engaged and working as a magazine columnist. Mab is married with two kids. Meanwhile, Beth is scheduled to have a lobotomy performed which happens to be the day after the royal wedding between Prince Philip and Princess Elizabeth. Giles Talbot, one of the BP cryptographers and their friend from the book club, comes to see Beth and admits that he was the traitor. He says he can get her out, but will only do it if Beth agrees to turn over any evidence she has of his treason. Beth refuses. He says she has until the lobotomy to change her mind.

With a little over a week before the lobotomy is scheduled, Osla and Mab finally show up to Clockwell. They talk to Beth and realize she is telling the truth, though Osla is shocked by the revelation because Giles is her fiancé. Still, by causing a distraction and stealing a set of keys, they help her to escape. From there, they need to get evidence that affirmatively identifies Giles as the traitor before he learns Beth has escaped (which he'll know when he checks in on her the day of her scheduled lobotomy). They retrieve the rest of the files encrypted with the Rose Code, and Beth gets to work on decoding it.

With only a few days left, Mab gets the idea to call Beth's old cryptography colleague, Harry, who had believed her to be dead. Harry calls in a bunch of other people and soon one of them is able to get access to the machinery they need, a bombe machine and an Enigma machine. They bring in a bombe technician that turns out to be Mab's husband, and they realize they've both been keeping their histories secret due to the oath of secrecy they took.

The cryptographers crack the code and they get the evidence they need against Giles just after midnight on the day of the royal wedding. After an extended interlude, they are able to apprehend Giles, though everyone gets arrested. Osla happens to be wearing Mr. Cornwell's coat (which she kept all these years), so he gets called in (the police assume he is her husband) and they finally meet again. Osla then phones her ex-beau, Prince Philip, to help untangle this mess.

In the end, Beth is free and back together with Harry. She also has an offer to continue working on codebreaking for the government. Mab and her husband are able to have a closer relationship now that they know about each others' pasts. And Osla marries Mr. Cornwell and pursues a career as a magazine columnist. The book ends with the announcement of Bletchley Park reopening (as a tourist destination) in 2014.

For more detail, see the full Chapter-by-Chapter Summary.

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