“Because of us,” Binnie said. “Alf and me. She’d promised she wouldn’t leave us. And she needed to be here to tell you where Polly and Mr. Dunworthy were.”

And so she’d sacrificed herself and stayed behind. But there must be some other way, especially since she wasn’t the one who’d told him; Binnie was. But he could deal with that later. Just now, he needed to find out where they were.

“Binnie,” he said eagerly, “we’ve got to come up with times when they were together in one place. You said Eileen made the decision to stay—which means she must have been there as well—so it has to be a time when all three of them were together. Before the first of May. That’s when Mr. Dunworthy’s deadline is. I’m assuming the best time for them to be together is during a raid. Did they go to a tube shelter during the raids?”

“Yes, but—”

“And you need to tell me where they’re living and what times they’re likely to all be at home. I know about Mrs. Rickett’s. Are they still in Kensington? If they are, then that may mean the drop Polly used will open—”

Binnie was frowning at him.

“I know this was a long time ago,” he said, “and it’s difficult to remember exactly where they were at any given time, but this is critical. If you can’t remember an exact date, then if you can just tell me which tube shelter, I can look up the dates when there were raids and—”

She shook her head, still frowning.

“Why won’t that work?” he said. “Did they not always go to the tube station when there were raids?”

“It doesn’t matter whether they did or not,” Binnie said. “That isn’t where they were.”

“Where they—”

“When you came.” She smiled at his uncomprehending look. “You’re forgetting, this all happened already. Over fifty years ago. Mum stayed behind so she could be here to make it happen, to tell you where they were.” She smiled ruefully. “And when she couldn’t be—”

“She sent you.”

“Yes.”

“She told you who she was?” he said, trying to process all this.

“Yes, but we’d worked it out on our own ages before that. When we were at the manor, we followed her out to the drop.”

“You saw her go through?” The drop wasn’t supposed to have opened if anyone was nearby.

“No, but we saw her just after she’d come back, and there were lots of other clues, mistakes and things, and then when you came and took Polly and Mr. Dunworthy, we were dead certain. Only there’s still a good deal we don’t know. Like why it took you so long to get here.”

“None of the drops in England in 1940 would open,” he said. “When Mr. Dunworthy didn’t return, we tried every possible temporal and spatial location, and nothing would work. At first, we thought it was every drop, but the ones in other places and times weren’t affected, just those in England and Scotland and the first three months of 1941. We could get a few drops to open after mid-March, but by then we had no idea where they were. Polly’d left Townsend Brothers, and they weren’t at Notting Hill Gate.”