attempt to catch my train. I was feeling drowsy and stupid, partly from my dinner and also from the effects of a long day’s work. A cup of coffee would clear my brain. A commissionnaire remains all night in a little lodge at the foot of the stairs, and is in the habit of making coffee at 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 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. Halfway 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 shortcut 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.