his spirit-lamp for any of the officials who may be working
over time. 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
commissionnaire'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 and walked up and down the room to stretch my legs. My coffee had
not yet come, and I wondered what was the cause of the delay could be.
Opening the door, I started down the corridor to find out. There was a
straight passage, dimly lighted, which led from the room in which I
had been working, and was the only exit from it. It ended in a curving
staircase, with the commissionnaire's lodge in the passage at the
bottom. Half way down this staircase is a small landing, with another
passage running into it at right angles. This second 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 the stairs and into the hall, where I found the
commissionnaire fast asleep in his box, with the kettle boiling
furiously upon the spirit-lamp. I took off the kettle and blew out the
lamp, for the water was spurting over the floor. Then I put out my hand
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 me and
then up at the 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 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. Some one, then, was in that
room where my precious treaty lay upon the table. I ran frantically up
the stair and along the passage. There was no one in the corridors, Mr.
Holmes. There was no one in the room. All was exactly as I left it, save
only that the papers which had been committed to my care had been taken