I picked up the telephone book and looked up the number of his house. We were connected at once, and I heard a servant’s voice.

“Is his Lordship at home?” I asked.

“His Lordship returned half an hour ago,” said the voice, “and has gone to bed. He is not very well tonight. Will you leave a message, sir?”

I rang off and almost tumbled into a chair. My part in this business was not yet ended. It had been a close shave, but I had been in time.

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.