第三週：模仿遊戲

The Imitation Game

    In 1951, two policemen, Nock and Staehl, investigate a break-in at the home of mathematician Alan Turing, whose suspicious behaviour and absence of war records causes Nock to believe that Turing may be a Soviet spy. The police send a man to follow Turing into a pub, where he hands an envelope to a male prostitute, who is arrested shortly afterward and confesses that Turing is a client. Staehl is ready to charge Turing with gross indecency, but Nock is still convinced that Turing is a spy, and begs Staehl to let him interrogate Turing for half an hour, whereupon the latter begins to disclose his top-secret activities during the war.

    In 1939, after Britain declares war on Germany, Turing is accepted by Commander Alastair Denniston, of the Royal Navy, for a code-breaking job at Bletchley Park, working alongside Hugh Alexander, John Cairncross, Peter Hilton, Keith Furman, and Charles Richards. They are instructed to break the Enigma codes that the Germans use to encrypt their communications, which, as Maj Gen Stewart Menzies of MI6 explains, allows them to attack British and American shipping, leading to famine and the loss of life.

    Turing works in isolation from the others, to the disappointment of his colleagues, and he concentrates all of his efforts in creating a decryption machine, instead of decoding by hand. When Denniston refuses to fund the machine's construction, Turing writes to Winston Churchill, who arranges the funding and names Turing as the team leader. Turing immediately fires Furman and Richards, who are linguists rather than mathematicians, and orders the others to construct the machine with him.

    There is a flashback to 1928 when Turing was in the boys-only Sherborne School, where he was bullied by other pupils but was rescued by a boy named Christopher Morcom. The latter introduces him to recreational cryptography and arouses Turing's romantic feelings, but dies after the spring break from bovine tuberculosis, leaving Turing scarred.

    Turing's team, which needs more people, places a crossword puzzle in the newspaper and conducts a mathematical examination for candidates, eventually selecting Joan Clarke and Jack Good. Clarke is prevented by her parents from working with an all-male team, so Turing asks her to become one of the telegraph clerks, who are female, and conveys cryptographic materials to her living quarters in secret.

    The machine is eventually finished, and Turing names it 'Christopher', but it takes too long to execute, whereas the ciphers of Enigma are changed on a daily basis. Denniston orders the machine to be destroyed and Turing fired, but the other cryptographers threaten to quit. Denniston relents and says he will give the team one month to decode an encrypted German message with the machine.

    During this time, Clarke's parents pressure her to leave Bletchley because she is unmarried and alone, and they want her home, so Turing proposes to her so she can stay. At the engagement party, Cairncross advises Turing he is aware of his homosexuality, but warns him to keep it from Joan due to the risk of being caught. During an evening at a local pub, Hugh begins to flirt with a colleague of Joan's named Helen. As they flirt, Helen jokes how she has a crush on a German but cannot pursue him, because she suspects he has a girlfriend based on the messages. Turing asks how she knows, and Helen clarifies that because the messages start with the same word, she suspects that must be someone's name. Because of this, Turing realises that the machine can be sped up by prerecognising routine phrases such as "Heil Hitler" and others from daily weather reports, and the recalibrated machine starts to quickly decode transmissions. However, the team realises that, should the Royal Navy act on the new information, the Germans may realise the Enigma code is broken and redesign it, thereby voiding the team's work.

    As such, the team conceals the success of the machine from Denniston and delivers the results to Menzies, who uses his influence to prevent the team from being fired. Menzies works with the team to determine which pieces of information can be used while arousing the least German suspicion. Around this time, Turing discovers that Cairncross is a Soviet spy, but Cairncross argues that the Soviets are allied with the UK and threatens to expose Turing's homosexuality if he tells anyone.

    Turing finds Menzies in Clarke's home, suspecting her of being a spy. When Turing reveals that the spy is Cairncross, Menzies explains that he already knew and has been using Cairncross to leak information of low importance.

    Shortly afterwards, fearing that Clarke is in trouble because of her secret involvement with the team, Turing reveals to her that he is a homosexual, hoping to drive her away. She is unfazed by this, and Turing lies that he has never cared for her. They break up, but she refuses to leave.

    As the war ends, Menzies tells the team to destroy all of their work and never speak of their achievements to the world.

    In 1951, back in the interrogation room, Nock is stunned by the story and says that he cannot judge Turing. However, Staehl has the charges pressed, and Turing is given a choice of two years in prison or chemical castration; Turing chooses the latter. He is visited at home by Clarke, who witnesses his physical and mental deterioration. She comforts him by saying that his work saved millions of lives.

    In the end, the team is shown in 1945 burning all of their documents, and a caption reveals that Turing committed suicide in 1954, aged 41.

Web address: https://en.wikipedia.org/wiki/The_Imitation_Game

Introduction Analysis:
What: British cryptanalyst Alan Turing , who decrypted German intelligence codes for the British government during World War II.
Who: Alan Turing
When: World War II 

Key words: 
mathematician 數學家
gross indecency嚴重猥褻

interrogate審問
disclose透露

encrypt加密

decryption machine解密機

bovine tuberculosis牛結核病

crossword puzzle填字遊戲

cryptographers密碼學家

homosexuality同性戀