Sitting on the plane, Jean compared the images of stolen books given away by Columbia House that she had received via email over the past few hours. Four books, including the one she had received. What she saw might have surprised her a few days ago, but now seemed perfectly in keeping with what she knew about Ingrid Weiss. Each of the books bore some sort of inscription that identified it as belonging to a relative of the person to whom Weiss had sent it. But each of those inscriptions was in the same handwriting. Jean had no doubt that the books were stolen and the inscriptions forged. And Peter Byerly was right—she should probably just phone the police in Munich and let them confront Ingrid Weiss.

But Jean tended to take things personally. It happened whenever a student gave her a bad review on one of those “rate your professor” websites or when a man failed to call her for a second date. She often couldn’t shake those sorts of rejections for several days and now she couldn’t shake this. Ingrid Weiss had tried to dupe her. For what reason, Jean could not imagine, but some stranger in another country had picked out Jean as a sucker and tried to make her grateful for possessing stolen merchandise. She didn’t want the Munich police to arrest Ingrid Weiss for fraud and theft quite yet. Just as she always wanted to confront that anonymous student or that man who didn’t share his phone number, Jean wanted to confront Ingrid Weiss. She had the ammunition, in the form of incontrovertible evidence, and this time she had something she didn’t have when a student reviewed her or a man didn’t call. She had an address.

The drums on the front of the Bombe clicked as they rotated and the motor that drove the mechanism throbbed. “Imagine a room full of these things,” said Ruthie, “all running at the same time. At the height of the codebreaking operation, the noise in the Bombe huts was deafening.”