“I thought I saw someone,” Polly said.

“Who? Agatha Christie?”

“No, an historian. Jack Sorkin.”

“I thought he was in the Pacific.”

“I know, but I could have sworn …,” Polly said.

They reached the top of the escalator. Polly looked around at the crowd, frowning. “Oh, it isn’t him, after all,” she said, pointing at a sailor on the far side of the hall. “Too bad.”

“It’s all right,” Eileen said. “We can still go to the canteen.” She started over to the escalator to go back down.

“Wait, I’ve just had a brilliant idea,” Polly said. “Let’s go to Lyons Corner House instead.”

“Lyons?” Eileen repeated doubtfully. “Why?”

“There aren’t any raids tonight. They’re bombing Bristol. We can have a proper meal, and you can tell me all about Murder in the Whatever It Is.”

“The Calais Coach,” Eileen said. “Do you think they may have bacon at Lyons? Or eggs?”

They had both, and tea that didn’t taste like dishwater. And pudding that didn’t taste like wallpaper paste.

“That was the most wonderful meal I’ve ever had,” Eileen said blissfully on the train home. “I’m glad you thought you saw Jack.”

“You were going to tell me about Murder in the Calais Coach,” Polly said.

“Oh. Yes. It’s wonderful. Everyone has a motive for the crime, and you think, ‘It can’t be all of them. It’s got to be one or the other,’ but then it turns out … but I don’t want to spoil it for you. Would you care to borrow it? I’m sure the librarian at Holborn wouldn’t mind if I kept it a bit longer.”

Polly wasn’t listening. She was thinking about the slippage and their altering events. “Eileen,” she asked, “did Linna or Badri say anything about what was causing the increase in slippage?”

“No, not that I remember,” Eileen said, and when they got back to their room, she handed Polly a sheet of paper. “Here, I wrote down everything I could remember, the way you and Mike told me to.”

On the sheet was scrawled, “G had umbrella, ddn’t offer it—Badri wking console—Linna on tphne—mad abt. Bastille—L sd she kn R of T first.”

“What’s R of T?”

“The Reign of Terror. Linna was talking to this person on the telephone about the lab changing whoever it was’s drop to the storming of the Bastille, and the person on the other end was obviously angry, and she said, ‘I know you were scheduled to go to the Reign of Terror first.’ But she didn’t say anything about slippage to them.”

Whoever it was had been scheduled to do the Reign of Terror, and they’d changed it so he or she went to the storming of the Bastille. Which had happened before the Reign of Terror.

“Where was Mike going before his assignment got changed to Dunkirk?” she asked Eileen. “Was it Pearl Harbor?”

“I don’t know. I believe so. They’d changed his entire schedule.”

“Where else was he supposed to go?”