When I entered that quiet thoroughfare it seemed deserted. Sir Walter's house was in the narrow part, and outside it three or four motor-cars were drawn up. I slackened speed some yards off and walked briskly up to the door. If the butler refused me admission, or if he even delayed to open the door, I was done.
He didn't delay. I had scarcely rung before the door opened.
'I must see Sir Walter,' I panted. 'My business is desperately important.' That butler was a great man. Without moving a muscle he held the door open, and then shut it behind me. 'Sir Walter is engaged, Sir, and Ihave orders to admit no one. Perhaps you will wait.'
The house was of the old-fashioned kind, with a wide hall and rooms on both sides of it. At the far end was an alcove with a telephone and a couple of chairs, and there the butler offered me a seat.
'See here,' I whispered. 'There's trouble about and I'm in it. But Sir Walter knows, and I'm working for him. If anyone comes and asks if I am here, tell him a lie.'
He nodded, and presently there was a noise of voices in the street, and a furious ringing at the bell. I never admired a man more than that butler. He opened the door, and with a face like a graven image waited to be questioned. Then he gave them it. He told them whose house it was, and what his orders were, and simply froze them off the doorstep. I could see it all from my alcove, and it was better than any play.
I hadn't waited long till there came another ring at the bell. The butler made no bones about admitting this new visitor.
While he was taking off his coat I saw who it was. You couldn't open a newspaper or a magazine without seeing that face - the grey beard cut like a spade, the firm fighting mouth, the blunt square nose, and the keen blue eyes. I recognized the First Sea Lord, the man, they say, that made the new British Navy.
He passed my alcove and was ushered into a room at the back of the hall. As the door opened I could hear the sound of low voices. It shut, and I was left alone again.
For twenty minutes I sat there, wondering what I was to do next. I was still perfectly convinced that I was wanted, but when or how I had no notion. I kept looking at my watch, and as the time crept on to half-past ten I began to think that the conference must soon end. In a quarter of an hour Royer should be speeding along the road to Portsmouth ...
Then I heard a bell ring, and the butler appeared. The door of the back room opened, and the First Sea Lord came out. He walked past me, and inpassing he glanced in my direction, and for a second we looked each other in the face.
Only for a second, but it was enough to make my heart jump. I had never seen the great man before, and he had never seen me. But in that fraction of time something sprang into his eyes, and that something was recognition. You can't mistake it. It is a flicker, a spark of light, a minute shade of difference which means one thing and one thing only. It came involuntarily, for in a moment it died, and he passed on. In a maze of wild fancies I heard the street door close behind him.
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. '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 scarcelyleft 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.
