Not a moment could be lost, so I marched boldly to the door of that back room and entered without knocking.

Five surprised faces looked up from a round table. There was Sir Walter, and Drew the War Minister, whom I knew from his photographs. There was a slim elderly man, who was probably Whittaker, the Admiralty official, and there was General Winstanley, conspicuous from the long scar on his forehead. Lastly, there was a short stout man with an iron-grey moustache and bushy eyebrows, who had been arrested in the middle of a sentence.

Sir Walter’s face showed surprise and annoyance.

“This is Mr. Hannay, of whom I have spoken to you,” he said apologetically to the company. “I’m afraid, Hannay, this visit is ill-timed.”

I was getting back my coolness. “That remains to be seen, sir,” I said; “but I think it may be in the nick of time. For God’s sake, gentlemen, tell me who went out a minute ago?”

“Lord Alloa,” Sir Walter said, reddening with anger.

“It was not,” I cried; “it was his living image, but it was not Lord Alloa. It was someone who recognized me, someone I have seen in the last month. He had scarcely left the doorstep when I rang up Lord Alloa’s house and was told he had come in half an hour before and had gone to bed.”

“Who⁠—who⁠—” someone stammered.

“The Black Stone,” I cried, and I sat down in the chair so recently vacated and looked round at five badly scared gentlemen.