“Look, Lady Furness is lunching with a friend in the restaurant downstairs. Do you want me to go and find her to tell you that it’s all right for me to go in there?”

She looked at me long and hard, then she said, “No, I suppose it can’t do no harm, can it? But the bed’s already been stripped. If it hasn’t been found yet, chances are it’s not going to be.”

“A little diamond could have fallen down the back of the bed and nobody would notice it,” I said. “Anyway, I’ve been commanded to search and search I’d better, or else. You should see her when she gets rattled.”

She grinned at me then. “Go on, then, in you go and make sure you shut the door firmly behind you. I don’t want to get in trouble for leaving a door open.”

“Oh, definitely. I’ll make sure I shut it,” I said. “I’ll even keep it shut while I’m searching.”

She opened the door. I went inside and shut it behind me. I wasn’t quite sure what use it was being in room 313, but it was better than nothing. I opened the window and saw that there was a broad ledge running around the outside. If the window of 317 was not latched tightly, it was possible I might get in that way. I climbed out gingerly onto the ledge. It was certainly a long way down. I could see the parade of bright red buses passing below me along the Strand. And that broad ledge didn’t seem so broad any longer. I didn’t have the nerve to stand up. I started to crawl slowly along the ledge. I passed 315 successfully and reached 317. It was hard to get any purchase on the window frame from my precarious position, but at last I felt it give a little.