Chapter 319: That’s worth a few sleepless nights.

Words : 1110 Updated : Oct 5th, 2025

The morning in Section V began with the clatter of Henri’s typewriter. Alan Turing arrived just as the latest strip of intercepts rolled out, still warm from the machine. "Morning, Monsieur Turing," Henri said without looking up. "Batch from the Vosges station. Picked up just after midnight. Same format, three groups of five letters." Turing pulled the sheet from the typewriter and scanned it as he walked toward the long bench where Luc and Jean-Pierre were already unpacking small wooden crates. "What’s in there?" Turing asked, setting the intercepts down. "Rotors," Luc replied, lifting one from its wrapping. "Blank units from the machine shop, waiting to be wired." Turing leaned in to inspect it. "Bakelite core, metal contacts... good. We’ll need at least a dozen wired in different permutations before we can begin meaningful testing." Jean-Pierre frowned. "Do you know the wiring?" Turing hesitated. "Not exactly. But I know enough to design tests that will narrow the possibilities." Henri walked over, wiping ink from his fingers. "Do the Germans change the wiring often?" "Almost never," Turing said. "It’s fixed inside the rotor, so it would require building an entirely new set for every machine in the field. Too slow. What they do change is the order of the rotors, the ring settings, and the plugboard connections." Luc placed the rotor gently on the bench. "So, the wiring is the skeleton. The settings are the flesh." "Exactly," Turing replied. "And if you understand the skeleton, you can predict how the flesh will move." Jean-Pierre began aligning the rotors in a wooden jig he had made. "We could wire three this week. Maybe four if André gets the contact pins on time." Henri glanced toward the far table where a pile of messages lay unsorted. "And in the meantime?" Turing picked up one of the sheets. "We look for the lazy operator." Luc raised an eyebrow. "Lazy?" "Every system has them," Turing said. "Men who follow procedure most of the time but cut corners when they think no one is watching. Maybe they send a weather report twice with the same key. Maybe they write a name they shouldn’t. A repeated pattern is worth more than a hundred random messages." Jean-Pierre smirked. "And how do we find this lazy man among thousands?" Turing tapped the stack of intercepts. "We read everything. Twice." Henri groaned. "We’ll go blind." "Better blind than ignorant," Turing replied, already sorting messages into piles by date and origin. By midday, the benches were crowded with piles of paper, loose sheets marked with quick pencil notations. Luc and Jean-Pierre worked quietly at the wiring jig, their hands stained with graphite. Henri sat across from Turing, reading out letter groups. "Batch 204. Message one: O-V-Q-K-L, Z-E-M-F-R, K-U-P-X-Q..." Turing’s pencil moved rapidly. "Again." Henri repeated it. "Now batch 205," Turing said. Henri read from the next sheet. Turing underlined something. "There. The first group in both messages starts with O-V-Q. Same origin point?" Henri checked his notes. "Both from a station outside Stuttgart." Luc looked up. "Coincidence?" Turing shook his head. "Probability says otherwise. It’s possible the same operator reused a setting for two messages. If so, they’ll share an identical initial key sequence before diverging." Jean-Pierre leaned back. "So, if we get two messages with the same starting sequence, we can compare them and..." "Find the point where they differ," Turing finished. "Which will give us clues about the rotor positions." Henri squinted at the page. "It’s like listening to two musicians play the same piece, but one makes a mistake halfway through." "And that mistake tells you how their instrument is tuned," Luc added. Turing smiled faintly. "Precisely." In the afternoon, André Vidal arrived with a flat wooden case. "Contacts from Lyon," he announced. "Best we can get without attracting questions." Luc opened the case and examined the tiny brass fittings. "Good. These will make the connections clean." Turing walked over. "Can you have one rotor wired by tonight?" Luc nodded. "If I work through supper." "Do it," Turing said. "The sooner we can test the drum sequence, the better." Henri returned to the typewriter, his fingers striking out new intercepts as they arrived by teleprinter. Turing drifted between benches, checking Luc’s wiring work and Jean-Pierre’s mechanical tolerances. Jean-Pierre held up a small rotor housing. "Clearance is tight. If we add more than ten drums in series, the frame will have to be extended." "Extend it," Turing said without hesitation. "Speed matters more than size. We’re not putting this in the field it stays here." Henri glanced over his shoulder. "What happens if the Germans add a fourth rotor like the navy uses?" Turing stopped for a moment. "Then we’ll adjust. But that’s unlikely for the army this year it would require a massive retraining effort. They don’t think they need it yet." Luc smirked. "Arrogance our ally." By five o’clock, the first rotor was wired. Luc placed it gently into the jig, and Turing rotated it slowly, testing continuity with a hand-held probe. "Connections clean," Turing said. "Good work." Henri brought over a fresh intercept. "This just came in. Repeated letter groups again see here?" Turing studied it. "Same Stuttgart station. Our lazy operator strikes again." Jean-Pierre leaned in. "Two hits in one day?" "Possibly," Turing said. "Or possibly this is standard for that station. Either way, it’s useful." Luc asked, "So what’s next?" "We build the rest of the rotors," Turing replied. "Then we simulate the machine with the intercepted keys and see which settings reproduce these sequences. Once we can predict one day’s key, the rest becomes pattern recognition." Henri grinned. "And pattern recognition is your specialty." Turing allowed himself the smallest of smiles. "Among other things." Evening settled over Paris, but the lights in Section V burned on. Luc and Jean-Pierre worked side by side at the jig, André sorted contacts into small glass jars, and Henri continued typing intercepts. Turing stood at the chalkboard, filling it with long columns of numbers and letters, arrows connecting them in intricate webs. Luc glanced up from his bench. "You know, I’ve built a lot of machines. Radios, transmitters, even a cinema projector. But I’ve never built something designed entirely to outthink another machine." Turing didn’t turn from the board. "That’s what makes this work different. We’re not just building we’re anticipating." Henri looked at him. "And what happens when we succeed?" Turing finally faced them. "Then we’ll be reading their orders before their own soldiers have finished marching." The room went quiet for a moment. Luc broke the silence. "That’s worth a few sleepless nights." Turing nodded. "It is. Now, let’s make sure they’re not wasted."

Chapter 319: That’s worth a few sleepless nights.

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