Room to Let. It took a moment for that to sink in, and then he was up the steps and pounding on the door. A plump, rosy-cheeked old lady opened the door a sliver, smiling. “Yes?”

“I saw that you have a room. Is it still available?”

She stopped smiling and folded her arms belligerently across her stomach. “Did the billeting office send you?”

If he said yes, he might have to produce some sort of official form, and if he said no, she was likely to tell him all her rooms had already been co-opted. “I saw your notice,” he said, pointing at it. The smile came back, and she motioned him to come in.

“I’m Mrs. Jolsom,” she said. “I didn’t think you looked like one of them.”

Polly and Eileen won’t be happy about that after all their efforts, he thought, wondering what was wrong with his appearance.

“I don’t let rooms to that lot at the Park. Unreliable. Coming and going at all hours, scattering papers everywhere, and when you try to tidy up after them, shouting at you not to touch anything, like it was something valuable instead of a lot of papers covered with numbers. Ten and four.”

For a moment he thought she was talking about the numbers on the papers, then realized she meant the price of the room. “Paid by the week. In advance,” she said, leading him upstairs. “Room only, no board—the rationing, you know. I ask two weeks’ notice if you’re leaving,” she said, leading him up a second flight, “so the room won’t stand empty.”

She apparently hasn’t heard about Wendy having to sleep in the pantry, Mike thought, following her down a hall. The room was the size of a closet, but it was a room and in Bletchley. “I’ll take it,” he said.

“I’ve had them go off without a word,” she said indignantly. “Or not come when they said they would. And after I’d saved the room for them. ‘There must have been a miscommunication,’ the billeting officer said. ‘Miscommunication!’ I said. ‘What about this letter? And what about my four weeks’ rent?’ ”

Mike finally stopped her by handing her the week’s rent and asking if she had a telephone. “No, but there’s one at the pub two streets over,” she said. “Claimed he hadn’t sent the letter, he did. ‘Well, then, that’s the last one you billet here,’ I told him. ‘What about your patriotic duty?’ he says. ‘What about their patriotic duty?’ I says, ‘lazing about here messing with multiplication tables like a lot of schoolboys when they ought to be in the Army?’ ” She looked at Mike suspiciously. “Why aren’t you in the Army?”

He wasn’t about to blow it now, when this was the only room for miles, and in the one house where he wouldn’t have to worry about running into a famous cryptanalyst on the way to the bathroom. “I was injured at Dunkirk.” He pointed at his foot. “Dive-bomber.”