It was far more than that. What the Japanese were doing was encryption, and what Ann and her team were able to do, over and over, was unlock the encryption. They would work through the night to recover a key. They felt grudging admiration for how the enemy, even under attack, was able to cope with systems that demanded so much handwork, flipping through volumes and consulting tables. When Solomon Kullback received visitors, he liked to take them into a room with a table piled high with a sheaf of materials—codebooks, additive books, stacks of papers—and say, “These are the current materials which are being used by the Japanese.”
As the Arlington Hall veterans refined their training, they tried to understand what to expect from a newcomer. Wilma Berryman would give Annie, as she called her, a smattering of code groups—without telling her they came from a captured book—to see how many she could book-break. She was like a living cryptanalytic experiment. One year into her tenure, Ann began training enlisted men. Years later, when Solomon Kullback was asked whom he would want if he were stranded on a desert island and only one person could crack the message that would get him home, he didn’t hesitate: “Ann Caracristi.” The address unit also did its bit to shoot down Yamamoto. During that tense period after the first itinerary-related message was received, the U.S. Navy sent over for help on the address codes. Wilma recalled the episode as one of her team’s “biggest achievements,” though afterward, she said, the Navy did not like to admit the Army had helped. “The Navy took a lot of credit,” she said. “I was kind of unhappy.”
In the long-running beef between the U.S. Army and Navy, one of the Navy’s objections was that, by engaging a civilian workforce, the Army was likely to hire reckless, undisciplined people who could not keep a secret. This could not have been further from the truth. Sure, some people at Arlington Hall joked about what would happen if they blabbed. Signing the secrecy oath made them liable for prosecution, and a violation carried a fine of $10,000 or ten years in prison. Wilma liked to say nobody working on a civil servant’s salary “could ever have found ten thousand dollars,” so they’d just have to go to jail. But they took the secrecy oath in earnest. When Ann was asked what she did at Arlington Hall, she spoke in airy terms about clerical work.
They preferred not to have to explain things at all. The easiest way was to hang out with one another. The top Japanese Army code breakers ate lunch together and dined in the few local restaurants. Ann and Wilma and a few others even bought a sailboat together, pooling their funds to raise what was likely just a few hundred dollars, and struggling to sail in the wind-challenged Potomac River, where once they were almost mowed down by the night boat to Norfolk. It was dark, their sailboat was becalmed, and there was much horn blowing and hilarity. The code breakers formed a glee club and a theater group, played tennis, set up duckpin bowling in the alleys of Clarendon and Colonial Village, two nearby neighborhoods. There was a lot of drinking. People played the piano and sometimes slipped beneath it, passed out from alcohol and exhaustion.
There were love affairs, and there were deep and abiding friendships. Ann became close friends with a former Kansas schoolteacher and aspiring writer named Gertrude Kirtland. Gert was gregarious and more extroverted than Ann, also sixteen years older, fiercely literary, and erudite. She had been recruited out of the University of North Carolina at Chapel Hill. Gert, a people person, soon transferred into the personnel operation, where she provided her friends with a direct conduit to the very top brass. Gert, Ann, and Wilma would save up their gas coupons and drive Wilma’s old car out for weekends in the rolling Virginia countryside around Leesburg.
But restorative weekends did not happen often. Tooth and nail they worked. No one jostled for promotion. All this, they knew, was temporary. The point was to win the war and get back to their regularly scheduled lives. One civilian woman complained often about her pay grade, and Ann thought her careerism was appalling. The goal was not to seek advancement. The goal was to serve the war effort. There was competition—with the Navy, with the British, with colleagues in Australia, with one another—but the point was just to get a solution first. They couldn’t get people to stop working. Linguists, if they had spare time, would help with logging. There was a huge snowstorm, and everybody managed to walk to work. There was a spirit that prevailed of collegiality, fun, dead earnestness, and intellectual gamesmanship that led to the next major break, one that would have a consequence on the war as important as—if less publicly celebrated than—the Battle of Midway.
Breaking the address code was a vital achievement, but it left unsolved the main Japanese Army codes. By the spring of 1943, the situation was dire. The staff at Arlington Hall, along with a companion unit in Australia, began concentrating on the system known as 2468, the “water-transport code” used by the Japanese Army to route its supply ships, or marus. The team knew that 2468 was an enciphered code and that buried somewhere were two four-digit groups that comprised the indicator, an embedded item that told which part of the additive book had been consulted. The indicator was the central, elusive clue, and people all over the world were working to find it. As late as March 1943, the effort felt hopeless. The team tried brute-force attacks, punching cards and doing IBM run after IBM run, coming up with hypotheses, raising their own hopes only to see them dashed.
“The mere statement of facts and figures can convey little idea of the more exciting and well-nigh incredible aspects of the work—all-night sessions, when each message was pounced upon as being perhaps the final link in a chain of cryptanalytic attack; the periods when the borderline between complete blankness and complete readability seemed dangerously close; the narrow margins by which the cryptanalysts, working in close collaboration with the traffic analysts, sometimes just ‘squeaked by!’” Frank Lewis would later write—romantically but accurately. “An account of these aspects would put any mere ‘spy thriller’ to shame.”