THE CRIB
While summer and early fall had scorched, Washington’s winter cold bit to the bone. Even more so than back home in Indiana. Isabel was swaddled in a thick pea-colored coat and wool cap, and working on her third cup of coffee. She had been transferred from working on JN-25—the main Japanese naval code—to Magenta, the complex cipher machine that had some of the best minds in the military banging their heads against the wall.
“So far, neither the British nor the Soviets have been able to break it,” Rawlings had told her on her first day, in his smooth Southern drawl.
“So what makes you think we will?”
He shrugged. “Just a hunch I have.”
In her experience, hunches had no place in cryptanalysis. But she kept her mouth shut. She was the new girl on the team, and that made her almost invisible. Which didn’t bother her a bit. She was used to being invisible. Not exactly a wallflower—at five-nine with midnight hair and ice blue eyes—Isabel nonetheless preferred to blend into the background. Growing up with her head in books or out wandering alone through the hemlock and ash trees had shaped her. She wasn’t out for fame and glory, never had been.
She just wanted retribution for the enemies who’d shot down her brother, who also had happened to be her best friend.
After a couple weeks on Magenta, Isabel could see why the machine had proved so elusive. Her tiny new team had been forced to construct a similar machine out of thin air. No one had ever seen the machine, not even a blueprint of it, and they were drawing conclusions based on bits and pieces of stolen intercepts. The machine in question resembled a typewriter crossed with a telephone switchboard and was full of wires and knobs and dials. Word was, Magenta was even tougher than Enigma, the German cipher machine. And Enigma was as tough as they came.
On this particular afternoon, Isabel was wishing that, along with Latin and French, she had learned Japanese in school. Sure, you didn’t need to know the foreign language in order to break the cipher, but it couldn’t hurt. One of the first rules in codebreaking was to understand how the language in question operated. That meant knowing which letters were most common, which letters went together in pairs or triplets, which vowels went with which consonants and so on. But the Japanese language was a far cry from English.
She had been staring at her charts and rows of letters for so long her eyes had begun to cross. Short periods of humming had started up, but she managed to quell them before getting glares from her coworkers. Frustrated, she set down her pencil, the fourth one of the day, and got up to take a break.
At Rawlings’s desk, she stopped and said, “Excuse me, sir. May I go outside and take a walk? I need to clear my head.”
Tamping down the humming seemed to also dampen her ability to see patterns, the numbers and letters appearing on the backs of her eyelids, moving and melding and shifting. Whenever she reached a dead end, walking tended to loosen the straps of her mind.
“It’s snowing,” he said.
“I don’t mind. I like the snow.”
“Fine, but don’t go catching pneumonia on me,” he said.
Outside, feathers of snow fell silently on the mall. A thin layer had begun to form on tree branches and all surfaces facing skyward. Isabel pulled her coat tight and headed down Constitution Avenue toward the Potomac, breathing out clouds. Pretty soon, her steps fell into an even rhythm and the letters appeared in her mind. Groups of six and groups of twenty.
While the naval code JN-25 used numbers, Magenta was a diplomatic code and it used letters. It was known that messages that could be pronounced were cheaper to send, and to be pronounceable, even if it was pronounceable gibberish, meant the group needed both vowels and consonants. Six vowels, twenty consonants. Over the past few months, Isabel’s team, using knowledge from the old Red machine, which had been cracked, were able to notice a pattern with the six-letter mechanism. They correlated frequencies of vowels quite easily. But how the twenty letters were enciphered still eluded them. Even with the new IBM machines to help.
Shuffling through the snow in a trance, Isabel arrived at the river and headed north along the pathway. A chill rose off the water, carrying scents of fish and boat engine oil. Letters were flashing through her mind at an alarming rate. Encrypting machines used switches or rotors to transpose letters. B might become F, and then L, and finally X. Depending on how many cycles, the pattern would eventually repeat. She ran through thousands of possibilities, still nothing materialized.
Rawlings had burst in that morning after a meeting with Admiral Williams, face red, and slammed down a stack of papers. It was unlike him to be so rattled. “Intel says something major is going down between Japan and Germany. We need to get this figured out. Yesterday.”
The air was so cold that ice had begun to form on the edges of the river. All the benches were empty, not a soul in sight, which was just how she liked it. The trees and the river didn’t mind her humming, and she walked along in a reverie, half-aware of her surroundings, and half-lost in her own mind. Letters swirled around. There had to be a pattern. The cycles had to repeat. Somewhere along the way, a hypothesis began to form in the space beneath her thoughts.
The best way to test this would be to find more than one long message, sent on the same day so that they had the same cipher key. And they needed a crib. Her heart rate ramped up as she turned to hurry back.
As usual, the marine at the door demanded to see her badge. Specialist Q.
Cheeks burning and hands numb, she ran into the room in a flurry and tapped on the glass door of Rawlings’s small office. “I had a thought,” she said to Rawlings, then paused before continuing.
He looked lightly put off. “And?”
“If we can find at least three long messages sent on the same day, and a crib, we might have a chance at unraveling Magenta.”
A crib was a string of plain language known to be in a cipher or coded message that offered a way in. The Japanese were famous for their formalities, and these often gave Isabel and her team an entry point. I am most honored to inform Your Excellency, and other such phrases, had been handed over by the State Department, who often had the words in English. These proved to be immeasurably valuable.
Rawlings stared at her for a moment, then said, “Well, what are we waiting for?”
Isabel rushed to the file cabinet out in the main room while Rawlings unfolded himself from his desk and announced to the team, “We need to find three long messages sent on the same day, and we need them now.”
Nora and the five other gals on watch scurried to the wall of cabinets and began banging drawers, pulling files and riffling through them. Rawlings and Dell, the only other man on the team, huddled together, plotting their approach. Isabel was well aware they’d done this kind of thing before, only to fall flat, and she had to work to keep her excitement in check. For every single success, there were a hundred failures.
“Long messages are fine and dandy, but we really need a crib,” Nora said.
Isabel loved how adeptly the women all adopted codebreaking lingo. It made her feel like part of a smart girls’ club. Something she had never experienced before. The only club she’d ever been in consisted of an old horse, two goats and a couple of collie dogs.
“One step at a time,” Isabel said, fingers black with ink.
Anna, the tall and outspoken blonde in the bunch, said, “You ask me, this is a wild-goose chase. Magenta is unbreakable. The sooner we accept that, the sooner we can get back to working on JN-25.”
“Now that’s a great attitude to have,” Nora said.
“Nothing wrong with being realistic. Someone around here needs to be,” Anna said.
Other than being exceptionally bright, Anna was poorly suited for this work. She was always too ready to give up and move on to the next best thing. She lacked patience and perseverance and possibly the dash of insanity that was required in order to be a top-notch cryptanalyst.
Two hours later, the group had lost a bit of steam. Their frantic searching had become more measured, more methodical. But this was how things went here. They all knew that. Still, it was hard to not feel discouraged.
Nora had found one long message dated November 25. Only a few words in the message had been cracked. They still needed two more. Rawlings sent Nora and Anita to Room 1616 to ask for help in finding messages. Not twenty minutes later they burst into the room, flushed.
Nora waved a file. “We got them. November 25, straight out of Tokyo!”
Rawlings smoothed his thin mustache and smiled. “Damn, ladies. Good work. Now, the crib. Does anyone remember a circular or anything else coming through that day?”
“That day is over a month ago, sir,” Anna said. “With all due respect, we’ve had thousands of messages come through since then.”
Rawlings responded with a hard glare, and Isabel swore the temperature dropped ten degrees. Everyone scurried to the other side of the room, where cribs were kept.
Speaking softly, so no one else could hear, Nora said, “If we—you—solve this thing, your chances of going to Pearl will go up to about five percent. From zero.”
“Thanks, that makes me feel better,” Isabel answered.
“But truly, I think it might be the only way to wake them up to seeing your brilliance.”
Behind them, Ellen Mary, also known as the most organized woman in the world, was quietly leafing through her own desk drawer and mumbling something to herself. She had a nearly photographic memory.
Isabel walked over. “What is it?”
“I think I recall a circular coming through that same day. It stuck out to me because it was the day before Thanksgiving.”
A circular was simply when Tokyo sent messages to the embassies using both the old machine and Magenta. These messages were gold, since the old machine had been cracked, and they could thus decipher the messages and then look for correlations with Magenta.
While everyone else was focused on haphazardly searching, Ellen Mary pulled out a slightly crumpled sheet of paper, set it on her desk and smoothed it out with long, pale fingers. Isabel leaned in to get a closer look. Letters and scribbles and more letters with lines through them. And a date: November 25.
“You never cease to amaze me, Em,” Isabel said.
Ellen Mary shrugged. “Just doing my job.”
Isabel called Rawlings and the group over. “Em here just found a crib.”
It was going to be a long night.