My gloved fingers reached for her sleeve, missed, and then caught in the belt of her coat. “Come inside and warm yourself for a quarter of an hour.” I added quickly, “It will do no harm.”

I could see that she was tempted-but she was also desperate to get away, on the point of pulling free when a gust of wind, stronger than before, buffeted both of us. I realized that her coat-unlike mine, which was meant to keep me warm-was well cut and fashionably thin, not designed for walking on a night like this one. It was intended for stepping out of a cab to enter a restaurant or theater. I wondered, fleetingly, if it was hers or if she had been given it by a mistress or found it in a charity shop. It was even possible that she’d been sacked, with nowhere to stay.

“Thank you, I’ll be all right,” she said, still keeping her face in the shadows. “Let me go. Please.”

I hadn’t been wrong about the tears. And to my surprise her voice matched the coat, well bred and well educated. I had no choice but to release her belt.

“No, you won’t be all right,” I told her bluntly, before she could hurry away. “You’ll make yourself ill. Pneumonia. Pleurisy. I’m a nursing sister, I’ve just returned from France. I know what I’m talking about.” I hesitated. “I won’t ask questions. Or try to stop you when you wish to leave. Warm yourself, have a cup of tea. There’s no one else about. I promise you.”

I had the outer door open now, and there was a lamp burning on the small table under the stairs. It must have seemed a haven in this weather. She hesitated an instant too long, and I touched her sleeve again, urging her inside. I myself was shivering with the cold now, and I knew she must be chilled to the bone. Even for a London December, it was unbearably wretched.

With an anxious glance over her shoulder, she preceded me through the door, then stood there in the small entry as if she couldn’t think what else to do.