After hours of thinking over the ramifications of those words, she finally fell into a restless sleep, but she woke before five as the predawn light seeped through her curtains. She reached for her cell phone, re-reading the message. “Ruthie, it’s Patton Harcourt, your summer fling from Harvard. I hope you still remember me, because I certainly remember you—especially those nights in the dorm with the window open. Good times. Now, I need your help. Can you meet me at the museum tomorrow night around midnight? I need to use the Bombe. This is a burner, so don’t text back. And don’t tell anyone.” It had been fifteen years since Ruthie attended that summer course at Harvard on the early history of computer codebreaking, but she remembered Patton Harcourt like it was yesterday—the pixie haircut, the not-so-innocent smile, and the eyes that stayed laser focused on Ruthie’s own even after three pints. And Patton had remembered Ruthie’s phone number—but then Patton had a way with numbers, among other things. Ruthie recalled Patton’s surprising talent at darts and her even more surprising talent at kissing—and more. A pretty girl had never flirted with Ruthie, and so of course, though she hadn’t told Patton, Ruthie took it all much too seriously. She didn’t understand it was a flirtation, a summer fling, a bit of fun and not a lifelong romance. So, when the course ended, Patton had flounced away and Ruthie had returned to England with a broken heart.

Now a tiny corner of Ruthie’s heart leaped when she read those first words—“Ruthie, it’s Patton Harcourt.” Patton didn’t just remember her, she remembered her fondly. She might have called their affair a summer fling, but she also used the phrase “Good times.” Yes, they had been, thought Ruthie. But Patton’s text was more than just a flirtatious reminder of a long-lost love. Patton Harcourt needed to use the Bombe, the machine that had been created to crack the Enigma Code. Why? Did she want to show it off to some other girlfriend, trading on an old acquaintance to impress a new one? And if so, why all the secrecy? Why a burner phone? Did Patton actually need to use the Bombe for its true purpose? Surely she knew there were easier ways to do that in this day and age.

But Ruthie didn’t care about the questions. In a few hours she would see Patton. Even if it meant nothing, even if Patton never stopped to think that Ruthie might still have feelings, might have ever had feelings, she would see her. And if Patton needed the Bombe, no one could do a better job with that than Ruthie. She rolled out of bed, ate breakfast, showered, and, for the first time since her cousin’s wedding last autumn, decided she would wear some makeup.