“Well, Mrs Channing,” I said confidently, “I am extremely desirous of discovering the whereabouts of Mabel Anson. I want to see her upon a rather curious matter which closely concerns herself. Can you tell me of any one who is intimate with them?”

“Unfortunately, I know of no one,” she answered. “The truth is, that they left London quite suddenly; and, indeed, it was a matter for surprise that they neither paid farewell visits nor told any of their friends where they were going.”

“Curious,” I remarked—“very curious!”

Then there was, I reflected, apparently some reason for the present tenant at The Boltons refusing the address.

“Yes,” Mrs Channing went on, “it was all very mysterious. Nobody knows the real truth why they went abroad so suddenly and secretly. It was between three and four years ago now, and nothing, to my knowledge, has since been heard of them.”

“Very mysterious,” I responded. “It would seem almost as though they had some reason for concealing their whereabouts.”

“That’s just what lots of people have said. You may depend upon it that there is something very mysterious in it all. We were such very close friends for years, and it is certainly strange that Mrs Anson has never confided in me the secret of her whereabouts.”

I remembered the old colonel’s strange warning on that evening long ago, when I had first met Mabel at his table. What, I wondered, could he know of them to their detriment?

I remained for a quarter of an hour longer. The colonel’s wife was full of the latest tittle-tattle, as the wife of an ex-attaché always is. It is part of the diplomatic training to be always well-informed in the sayings and doings of our neighbours; and as I allowed her to gossip on she revealed to me many things of which I was in ignorance. Nellie, her daughter, had, it appeared, married the son of a Newcastle shipowner a couple of years before, and now lived near Berwick-on-Tweed.

Suddenly a thought occurred to me, and I asked whether she knew Miss Wells or the man Hickman, who had been my fellow-guests on that night when I had dined at The Boltons.