“One sees something different each time one looks at it,” Mr. Humphreys had said, and it was true. This time Christ looked not bored, not frightened, but infinitely sorry for both of them.

Polly stepped forward and put her hand on Mr. Dunworthy’s sleeve. “It’s all right,” she said, and began to cry.

“But you do know, don’t you,” he said, “that you committed the murders?”

—AGATHA CHRISTIE, THE ABC MURDERS

London—Winter 1941

POLLY LOOKED AT MR. DUNWORTHY STANDING THERE IN front of The Light of the World, and for a moment she thought she must have been wrong, as she had been wrong that night outside St. Paul’s, and it wasn’t him after all, but only someone who resembled him.

He seemed far older than the Mr. Dunworthy she knew, and his shabby coat, his worn hat, had an authenticity Wardrobe could never have managed. And he looked so weary. Mr. Humphreys had said he was “troubled” and “not well,” but it was far worse than that. He looked exhausted, broken. Defeated. Mr. Dunworthy had never been defeated by anything in his life.

But Polly had known even before she saw him that it was him—and worse, that the man she’d seen looking up at the dome of St. Paul’s that night had been him, too. And the reason he looked so defeated, so … beaten, was that he was as trapped and helpless as she and Eileen were. He wasn’t here as a rescuer. He was a fellow castaway.

But the mere fact that he was here at least meant that Oxford still existed. They hadn’t altered history and lost the war. And Oxford hadn’t been destroyed in some catastrophe. Everyone there wasn’t dead. And even if Mr. Dunworthy was shipwrecked, too, he was here, and she was overjoyed to see him.

“I’m so glad—” she began, and he turned and looked at her, but there was no surprise, no joy in his face, and as she stepped toward him, he backed away from her till he came up hard against The Light of the World.

Oh, God, Mr. Humphreys had said he’d been injured by a bomb blast, that he’d been in hospital. Could he have suffered brain damage? Could that be why he’d stared at her without recognition that night, and why he looked so afraid now? Because he didn’t know her? “Mr. Dunworthy?” she said softly because Mr. Humphreys would be here any moment. “It’s me …”

“Polly,” he murmured. “It’s really you, isn’t it? It isn’t a dream? There were times in hospital when I thought that all of it—Oxford and time travel and you—was only a dream.”

“It wasn’t,” Polly said, “and I’m really here. Eileen—Merope’s here as well. She’ll be so glad to see you! This is wonderful!” She moved to embrace him.

“No,” he said, and put up his hands to ward her off. “Not wonderful. Not when you—”

“It’s all right. We already know about the drops not working. Michael—” She stopped herself in time. She would have to tell him about Michael’s death, but not yet. He didn’t look strong enough to bear it.