"It was a long document, written in the French language, andcontaining twenty six separate articles. I copied as quickly as Icould, but at nine o'clock I had only done nine articles, and itseemed hopeless for me to attempt to catch my train. I was feelingdrowsy and stupid, partly from my dinner and also from the effectsof a long day's work. A cup of coffee would clear my brain. Acommissionaire remains all night in a little lodge at the foot ofthe stairs and is in the habit of making coffee at his spirit-lamp forany 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 wasthe commissionaire's wife, who did the charing, and I gave her theorder for the coffee.

　　"I wrote two more articles, and then, feeling more drowsy than ever,I rose and walked up and down the room to stretch my legs. My coffeehad not yet come, and I wondered what the cause of the delay could be.Opening the door, I started down the corridor to find out. There was astraight passage, dimly lighted, which led from the room in which Ihad been working, and was the only exit from it. It ended in a curvingstaircase, with the commissionaire's lodge in the passage at thebottom. Halfway down this staircase is a small landing, with anotherpassage running into it at right angles. This second one leads bymeans of a second small stair to a side door, used by servants, andalso as a short cut by clerks when coming from Charles Street. Here isa rough chart of the place." (See illustration.)

　　"Thank you. I think that I quite follow you," said Sherlock Holmes."It is of the utmost importance that you should notice this point. Iwent down the stairs and into the hall, where I found thecommissionaire fast asleep in his box, with the kettle boilingfuriously upon the spirit-lamp. I took off the kettle and blew out thelamp, for the water was spurting over the floor. Then I put out myhand and was about to shake the man, who was still sleeping soundly,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 meand then up at the still quivering bell with an ever-growingastonishment upon his face.

　　"'If you was here, sir, then who rang the bell?' he asked."'The bell!' I cried. '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 inthat room where my precious treaty lay upon the table. I ranfrantically up the stair and along the passage. There was no one inthe corridors, Mr. Holmes. There was no one in the room. All wasexactly as I left it, save only that the papers which had beencommitted to my care had been taken from the desk on which they lay.The copy was there, and the original was gone."