“We know we’re stranded here,” she said instead, but he was shaking his head.

“You don’t know,” he said fiercely. “Polly,” he began, and then stopped, as if he couldn’t bear to tell her. And what could be worse than knowing they couldn’t get out? What could make him look so … Oh, God, she thought. It’s Colin. He came through with Mr. Dunworthy.

Colin had talked him into letting him come along. Or tricked him and ducked under the net at the last moment, as he had when he was twelve. Whichever, they had both been here, they’d both been hit by the bomb blast. And the fact that he was here alone, that he’d been at St. Paul’s alone on the twenty-ninth, could only mean one thing.

“Did Colin—?”

“Oh, my goodness!” Mr. Humphreys said, bustling up. “Do you two know each other? But what a happy coincidence! I knew I was right in thinking you should meet.” He beamed at both of them. “But I had no idea you were acquainted. How do you know Miss Sebastian, Mr.

Hobbe?”

“He taught me at school,” Polly said so Mr. Dunworthy wouldn’t have to answer.

“I told Miss Sebastian I thought you were a schoolmaster,” Mr. Humphreys said happily. “You knew so much about St. Pau—”

“And you were right, Mr. Humphreys,” she said. “Thank you so much for bringing us together and giving us this chance to visit,” she added, hoping he’d take the hint, but he took no notice.

“What was your subject, Mr. Hobbe?” he asked.

“History,” Polly said.

“I knew it! I told you he knew all about history, didn’t I, Miss Sebastian?” Mr. Dunworthy winced. “And I was right, you are an historian.”

She had to stop this, had to get Mr. Dunworthy away somehow. “Mr. Humphreys, I’m afraid we’re tiring Mr. Hobbe.”

She took Mr. Dunworthy’s arm. “You’ve only just got out of hospital. Perhaps—”

She had intended to say, “I should take him home,” but Mr. Humphreys was too quick for her. “Oh, of course, how thoughtless of me. Let me fetch you a chair.” He bustled off toward the nave.

The instant he was out of earshot, Polly said, “Mr. Dunworthy, it’s Colin, isn’t it? He came through with you, didn’t he?”

“Colin? No, I wouldn’t let him come.”

Polly’s knees nearly buckled from the force of the relief she felt, and she had to put a hand out to the pillar to steady herself.

“I wanted to get you out as quickly as possible,” Mr. Dunworthy said. “I was afraid the slippage might spike, and you’d be trapped here past your deadline.”

“But then why didn’t you come in September?”

“I did, but the slippage sent me through to December.”

Three months’ slippage. That meant the reason their drops hadn’t opened could have been because of slippage after all, and the entire first few months of the Blitz had been a divergence point. And now that the twenty-ninth was over …