It was something one of us did the night of the twenty-ninth, Polly thought. They had delayed the air-raid warden on the steps of St. Paul’s so that he hadn’t been in time to save someone. Or Theodore’s screaming departure had delayed the pantomime a crucial few minutes so that one of the audience hadn’t made it home to their Anderson in time. Or her presence on the roofs had altered the actions of the fire watch in some way that would prove fateful later on.

Or it might even have been Eileen’s taking the bombing victims to hospital or Mike’s saving the firemen. In a chaotic system, positive actions could cause negative outcomes. Like losing the war.

Winning it had always been a near thing. “We are hanging on by our eyelids,” Churchill’s chief of staff had said. Events had been balanced on a knife’s edge, and they had tipped the balance, and the Germans had won the war.

Oh, God, she thought, Hitler will execute Churchill and the King and Queen and Sir Godfrey, and send Sarah Steinberg and Leonard and Virginia Woolf off to die at Auschwitz, and Mr. Dorming and Mr. Humphreys and Eileen’s vicar off to die at the Russian front. He will breed the blondes, like Marjorie and Mrs. Brightford and her daughter Bess, to blue-eyed Aryans, and starve Theodore’s mother and Lila and Miss Laburnum. And turn Theodore and Trot into young Nazis.

But not Alf and Binnie, she thought. Or Colin, no matter what sort of world he’s born into. They’ll never go along with it.

Hitler would have to kill them first. And he would.

“Oh, God,” Polly murmured. “Mike was right. We lost the war. We ruined everything.”

“No,” Mr. Dunworthy said. “I did.”

I have got to know the worst, and to face it.

—SIR J. M. BARRIE, THE ADMIRABLE CRICHTON

London—Winter 1941

“WHAT DO YOU MEAN, YOU DID IT?” POLLY SAID, STARING at Mr. Dunworthy sitting there by the pub’s fire with her coat over his knees. He had stopped shivering, but he still looked chilled to the bone. “You can’t have lost the war. How? By coming to fetch me? Or something you did since you’ve been here?”

“No,” he said. “I did it before you and Michael and Merope were even born. When I was seventeen years old.”

“But—”

“It was the third drop we’d done to World War Two and the first to the Blitz. We were still refining the net coordinates, and all I had to do was to verify my temporal-spatial location and go back. I’d come through in the emergency staircase of a tube station, and when I found out I’d come through to the seventeenth of September 1940 instead of the sixteenth, I was frightened I might be in Marble Arch.” He stopped and stared bleakly into the fire. “Perhaps it would have been better if I had been.”

“Which station were you in?” Polly asked.

“St. Paul’s,” he said. “And when I found that out, I thought taking a side trip to see the cathedral couldn’t hurt.” He smiled bitterly. “I’d been fascinated by it since I first saw the fire watch stone as a boy. And here St. Paul’s still existed. So I ran up the street to look at it, just for a moment.”