the back room.

"Now, Watson, now!" cried Holmes, with frenzied eagerness. All the
demoniacal force of the man masked behind that listless manner burst out
in a paroxysm of energy. He tore the drugget from the floor, and in an
instant was down on his hands and knees clawing at each of the squares
of wood beneath it. One turned sideways as he dug his nails into the
edge of it. It hinged back like the lid of a box. A small black cavity
opened beneath it. Holmes plunged his eager hand into it, and drew it
out with a bitter snarl of anger and disappointment. It was empty.

"Quick, Watson, quick! Get it back again!" The wooden lid was replaced,
and the drugget had only just been drawn straight when Lestrade's voice
was heard in the passage. He found Holmes leaning languidly against
the mantelpiece, resigned and patient, endeavouring to conceal his
irrepressible yawns.

"Sorry to keep you waiting, Mr. Holmes. I can see that you are bored to
death with the whole affair. Well, he has confessed, all right. Come
in here, MacPherson. Let these gentlemen hear of your most inexcusable
conduct."

The big constable, very hot and penitent, sidled into the room.

"I meant no harm, sir, I'm sure. The young woman came to the door last
evening--mistook the house, she did. And then we got talking. It's
lonesome, when you're on duty here all day."

"Well, what happened then?"

"She wanted to see where the crime was done--had read about it in the
papers, she said. She was a very respectable, well-spoken young woman,
sir, and I saw no harm in letting her have a peep. When she saw that
mark on the carpet, down she dropped on the floor, and lay as if she
were dead. I ran to the back and got some water, but I could not bring
her to. Then I went round the corner to the Ivy Plant for some brandy,
and by the time I had brought it back the young woman had recovered and
was off--ashamed of herself, I dare say, and dared not face me."

"How about moving that drugget?"

"Well, sir, it was a bit rumpled, certainly, when I came back. You see,
she fell on it, and it lies on a polished floor with nothing to keep it
in place. I straightened it out afterwards."

"It's a lesson to you that you can't deceive me, Constable MacPherson,"
said Lestrade, with dignity. "No doubt you thought that your breach of
duty could never be discovered, and yet a mere glance at that drugget
was enough to convince me that someone had been admitted to the room.
It's l