“You’d travel together, of course. No one will question you. Why should they? The only one to attract attention is Jason and he won’t be with you. We won’t go on the same flight. I’d suggest I go with Jason on, say, a Sunday and you follow on the Monday. We meet by prearrangement—in a hotel, say—I hand him over and go back on the next flight.”

“I can’t agree to this,” Alison said.

Andrew gave her a cold look. “Why not? What’s wrong with it apart from the expense? It’s going to be bloody expensive.”

“The money doesn’t matter.” She made a throwing-away gesture, flinging out her hands. Her lined face contorted into wrinkles. “If this makes us destitute, my father will look after us. But I can’t be parted from Jason. And even if I could be, if I could bear that, Andrew and I couldn’t travel on the same plane. Suppose it crashed? Suppose we were both killed? Jason would be left alone again.”

“You know, I’m amazed sometimes at the nonsense people talk,” Andrew said. “Have you ever known someone set out on a car journey and ask what would happen if they were in a smash-up? No, of course you haven’t. But they’ve only got to get on an hour-long flight from London to Edinburgh to start imagining it’s going to crash.”

Silver looked from one to the other of them. “Would you think about it? Discuss it? You may be able to improve on it.” He paused. “And don’t worry. Don’t worry about the money.”

Once more we went down through the inside of the house. It was just after ten. There was no way of telling whether the Nylands were in bed or not, but as we passed on down the last flight of stairs, trying to be silent but not succeeding, the soles of our trainers slapping on those marble treads, the front door of Flat B opened. A man came out into the hall and looked up the stairs. Looked straight at us.

There were other people behind that door as we could tell by the sound of voices and laughter, but I supposed from Selina’s description that this must be Sean Francis. He was tall and thin and dark with that sort of feminine face that later became so fashionable, short nose, full mouth. I saw him in a television play last week and he seemed not to have aged at all. I suppose he was in his late twenties at that time. He said in a sharp voice, “What are you doing here?”

“Calling on the Nylands,” Silver said promptly.

“No, you can’t have been. They’re away.”