Scene 3: Hut in Bletchley Park, 1941
The hut is full of activity. Various SIDEKICKS attend to the workings of the Bombe, study slips of paper, look things up in dictionaries, smoke their pipes and fix their dottle stops. CUMBERBATCH is sitting at his desk, consulting his own paper Upon Computable Numbers and the Distinction Between the Ashes of the Various Tobaccos.
A bell rings.
CUMBERBATCH: That's it. It's midnight. The Germans have changed their cipher. Everybody stop what they are doing and put down their pens. Nothing we can do now until tomorrow morning when we get a new crop of intercepts, encoded with today's new rotor settings.
SIDEKICK: But I've nearly decoded this message. Only one cypher group to go!
CUMBERBATCH: Too late. Tear it up.
SIDEKICK: There's no reason to abruptly halt all decoding of existing material at midnight. The intelligence is still valid.
CUMBERBATCH: Last one out the hut, switch off C-C-C-Christopher.
SIDEKICK: It will only take about 10 minutes.
CUMBERBATCH: I won't tell you again.
Exit SIDEKICK. The head of MI6 appears, and accosts CUMBERBATCH.
HEAD OF MI6: Good evening. I'm the head of MI6. I'm here to arrest you as a traitor, Turing.
CUMBERBATCH, warmly: I'm not the traitor. It's C-C-C-Cairncross who is the traitor.
HEAD OF MI6: Fair enough. Well spotted. Good night.
CUMBERBATCH: What? Wait a minute. Do you mean to say that you know already? Aren't you going to arrest C-C-C-Cairncross?
HEAD OF MI6, amused: Of course we know. Arrest him? Why on Earth should I do that? No, he's much safer where he is, betraying all our secrets to the Russians.
CUMBERBATCH: But he is part of the Cambridge Ring that includes Burgess, Maclean and Philby, and makes British Intelligence a laughing stock for 30 years. Surely you must act.
HEAD OF MI6: What, and lose those lovely Alan Bennett plays? I should think not. We play a long game, here at Six.
CUMBERBATCH, whining: What does that even mean?
Scene 4: Same hut, the next day
CUMBERBATCH is doing "thinking" acting while studying a crossword. A clue wafts onto the screen, Moffat-style.
1. This Heli-hilter won't fly, but it's a common Nazi greeting (4, 6). (Anagram)
CUMBERBATCH: I've got it.
SIDEKICK: Got what?
CUMBERBATCH: In order to break the Enigma encryption, we need a sample of known text. The Germans always end all their messages with "Heil Hitler", so we can just use that.
KEIRA KNIGHTLEY, not being sarcastic: Alan, fancy noticing that after just a mere two years of war and countless thousands of messages. Even for you, that's brilliant.
CUMBERBATCH: Yes it is. And is it not ironic that the very device that the Nazis use to bind together their culture also turns out to be their key weakness?
KNIGHTLEY, still gushing: Neato. Well done, lover.
CUMBERBATCH: And, by the way, I am not going to marry you, you c-c-cow. I was just exploiting you for your brains. What is it, Hugh?
SIDEKICK, dialling a telephone: Using the technique just mentioned, I have rapidly decrypted some U-boat attack orders on a mid-Atlantic convoy which is to occur in fifteen minutes. There's just time to scramble a squadron of Spitties up from Biggin Hill to prevent a disaster.
CUMBERBATCH, cutting SIDEKICK off: No, you mustn't do that.
SIDEKICK: But you don't grok it, man. By a remarkable coincidence my only kid brother is on that particular convoy. We've got to stop the attack.
CUMBERBATCH: No way, Jose.
SIDEKICK: And Glenn Miller is aboard. And Rudolph Hess.
CUMBERBATCH: Doesn't change the plan, my man Juan.
SIDEKICK, shocked, bothered and bewildered: But why?
EDDIE IZZARD, who has just come in: I think I can explain.
SIDEKICK, startled: Who the feck are you?
IZZARD: I am the implausibly named Robert Watson-Watt. I invented radar. I feature in the BBC/OU co-pro film Castles in the Sky, which has essentially the same plot as this script: oddball, misfit inventor single-handedly wins the war, in the teeth of British military opposition.
IZZARD, patiently: If I shorten the war by two years, and Alan here also shortens it by two years...
CUMBERBATCH: At least three years...
SIDEKICK, finally getting there: Oh, I see. There'll be no proper war left for anybody to fight. And, more importantly, make movies about.
CUMBERBATCH: Right. So we both have to keep our benign influence down to 18 months or so. All that remains now is for us two to thrash out the spoils for posterity. You'll be the more obscure one, Robert, because of your silly name. I'll eventually get all the plaudits and the statues, especially if my life should happen to end tragically.
SIDEKICK: Just one moment, you two. What about me, Tommy Flowers?
CUMBERBATCH: I thought your name was Hugh.
IZZARD, dismissively: What did you invent? The upside-down hovercraft?
SIDEKICK: The first proper, working computer, actually.
CUMBERBATCH, in full Sherlock mode: What about the curious incident of Tommy's reputation in peace-time?
FLOWERS: My reputation was as nothing in peace-time.
TUTTI, to camera: That was the curious incident. ®