'Excuse me an instant,' said Holmes; 'were you alone during this conversation?'
　　'Absolutely.'
　　'In a large room?'
　　'Thirty feet each way.'
　　'In the centre?'
　　'Yes, about it.'
　　'And speaking low?'
　　'My uncle's voice is always remarkably low. I hardly spoke at all.'
　　'Thank you,' said Holmes, shutting his eyes; 'pray go on.'
　　'I did exactly what he had indicated, and waited until the other clerks had departed.One of them in my room, Charles Gorot, had some arrears of work to make up, so Ileft him there and went out to dine. When I returned he was gone. I was anxious tohurry my work, for I knew that Joseph, the Mr. Harrison whom you saw just now, wasin town, and that he would travel down to Woking by the eleven o'clock train, and Iwanted if possible to catch it.
　　'When I came to examine the treaty I saw at once that it was of such importancethat my uncle had been guilty of no exaggeration in what he had said. Without goinginto details, I may say that it defined the position of Great Britain towards the TripleAlliance, and foreshadowed the policy which this country would pursue in the eventof the French fleet gaining a complete ascendency over that of Italy in theMediterranean. The questions treated in it were purely naval. At the end were thesignatures of the high dignitaries who had signed it. I glanced my eyes over it, andthen settled down to my task of copying.
　　'It was a long document, written in the French language, and containing twenty-sixseparate articles. I copied as quickly as I could, but at nine o'clock I had only donenine articles, and it seemed hopeless for me to attempt to catch my train. I was fellingdrowsy and stupid, partly from my dinner and also from the effects of along day'swork. A cup of coffee would clear my brain. A commissionaire remains all night in alittle lodge at the foot of the stairs, and is in the habit of making coffee at hisspirit-lamp for any of the officials who may be working overtime. I rang the bell,therefore, to summon him.
　　'To my surprise, it was a woman who answered the summons, a large, coarse-faced,elderly woman, in an apron. She explained that she was the commissionaire's wife,who did the charing, and I gave her the order for the coffee.
　　'I wrote two more articles, and then, feeling more drowsy than ever, I rose andwalked up and down the room to stretch my legs. My coffee had not yet come, and Iwondered what the cause of the delay could be. Opening the door, I started down thecorridor to find out. There was a straight passage dimly lit which led from the room inwhich I had been working, and was the only exit from it. It ended in curving staircase,with the commissionaire's lodge in the passage at the bottom. Half-way down thisstaircase is a small landing, with another passage running into it at right angles. Thesecond one leads, by means of a second small stair, to a side-door used by servants,and also as a short cut by clerks when coming from Charles Street.
　　'Here is a rough chart of the place.'
　　'Thank you. I think that I quite follow you,' said Sherlock Holmes.
　　'It is of the utmost importance that you should notice this point. I went down thestairs and into the hall, where I found the commissionaire fast asleep in his box, withthe kettle boiling furiously upon the spirit-lamp, for the water was spurting over thefloor. I had put out my hand and was about to shake the man, who was still sleepingsoundly, when a bell over his head rang loudly, and he woke with a start.
　　' "Mr. Phelps, sir!" said he, looking at me in bewilderment.
　　' "I came down to see if my coffee was ready."
　　' "I was boiling the kettle when I fell asleep, sir." He looked at me and then up atthe still quivering bell, with an ever-growing astonishment upon his face.
　　' "If you was here, sir, then who rang the bell?" he asked.
　　' "The bell!" I said. "What bell is it?"
　　' "It's the bell of the room you were working in."
　　'A cold hand seemed to close round my heart. Someone, then, was in that roomwhere my precious treaty lay upon the table. I ran frantically up the stairs and alongthe passage. There was no one in the corridor, Mr. Holmes. There was no one in theroom. All was exactly as I left it, save only that the papers committed to my care hadbeen taken from the desk on which they lay. The copy was there and the original wasgone.'
　　Holmes sat up in his chair and rubbed his hands. I could see that the problem wasentirely to his heart. 'Pray, what did you do then?' he murmured.
　　'I recognized in an instant that the thief must have come up the stairs from theside-door. Of course I must have met him if he had come the other way.'
　　'You were satisfied that he could not have been concealed in the room all the time,or in the corridor which you have just described as dimly lighted?'
　　'It is absolutely impossible. A rat could not conceal himself either in the room orthe corridor. There is no cover at all.'
　　'Thank you. Pray proceed.'
　　'The commissionaire, seeing by may pale face that something was to be feared, hadfollowed me upstairs. Now we both rushed along the corridor and down the steepsteps which led to Charles Street. The door at bottom was closed but unlocked. Weflung it open and rushed out. I can distinctly remember that as we did so there camethree chimes from a neighbouring church. It was a quarter to ten.'
　　'That is of enormous importance,' said Holmes, making a note upon his shirt cuff.
　　'The night was very dark, and a thin, warm rain was falling. There was no one inCharles Street, but a great traffic was going on, as usual, in Whitehall, at the extremity.We rushed along the pavement, bareheaded as we were, and at the far corner we founda policeman standing.
　　' "A robbery has been committed," I gasped. "A document of immense value hasbeen stolen from the Foreign Office. Has anyone passed this way?'
　　' "I have been standing here for a quarter of an hour, sir," said he; "only one personhas passed during that time—a woman, tall and elderly, with a Paisley Shawl."
　　' "Ah, that is only my wife," cried the commissionaire.