Polly saw her to her train and then went to the British Museum—“Darling, so sorry. If you can forgive me, meet me by the Rosetta stone Sunday at two”—to wait for the retrieval team. And fret.

In spite of Mike’s reassurances that they hadn’t affected events, she was still worried. Her actions hadn’t affected only Marjorie. They’d also affected the warden who’d found her and the rescue squad and ambulance driver, her nurses and doctors, the airman she hadn’t met who’d gone off on his mission thinking she’d changed her mind about eloping, even Sarah Steinberg, who’d been given Marjorie’s job, and the shopgirl Townsend Brothers had hired to replace Sarah. The ripples spread out and out. And now Marjorie was going to be a nurse. She was going to be saving soldiers’ lives.

Like Mike had saved Hardy’s. And unlike Hardy, there was nothing else which could have caused what had happened. Marjorie had said quite plainly that she’d decided to run off with her airman because of having seen Polly standing there looking so shell-shocked the morning after St. George’s was hit. That had led directly to her having been in Jermyn Street when it was hit, and to her deciding to become a nurse and thus altering who knew what other events. Polly saw now why Mike had been so worried that morning outside Padgett’s when he thought he’d saved Hardy.

And now Mike was on his way to Bletchley Park, where he could do far more damage to the war than a hospital nurse could. If Gerald Phipps hadn’t already beaten him to it.

But if he had, there should be more discrepancies than just a siren going off when it shouldn’t have. And Mike was right, there were all sorts of instances in history when an action which should have had a major effect had been counteracted by something else, like the Verlaine-poem invasion signal. Or the appearance of “Omaha” and “Overlord” in the Herald’s crossword puzzle, which hadn’t affected the invasion after all.

But that was also an example of how a single small action could have tremendous consequences. A few words in a crossword puzzle had nearly derailed an invasion involving years of careful planning and two million men. If D-Day had had to be delayed, the invasion’s location would almost certainly have leaked out, and Rommel’s tanks would have been waiting for the invasion troops at Normandy. And all because of a bit of carelessness and a teenaged boy. “For want of a nail …”

So what sort of impact could the combined actions of Marjorie and Hardy, and Gerald’s and now Mike’s wandering around the place where the most important secret of the war was being kept have? If Mike got there. Just because he’d gone to Dunkirk didn’t mean he’d be allowed to reach Bletchley Park.

She gave the retrieval team another half hour to show and then went back to Mrs. Rickett’s to see if Mike had phoned. He hadn’t, and by the time Eileen returned, there’d still been no word from him. “Did you find out what the Hodbins were up to?” Polly asked her.