I placed the piece of silk upon the table, slightly shrugging my shoulders.
"It was sufficient evidence in itself," continued my friend, "but I thought it better to seek confirmation, and the obvious way was to pose as a new lessee of The Gables...."
"But, Smith—" I began.
"Let me explain, Petrie. The history of The Gables seemed to be susceptible of only one explanation; in short it was fairly evident to me that the object of the manifestations was to ensure the place being kept empty. This idea suggested another, and with them both in mind, I set out to make my inquiries, first taking the precaution to disguise my identity, to which end Weymouth gave me the freedom of Scotland Yard's fancy wardrobe. I did not take the agent into my confidence, but posed as a stranger who had heard that the house was to let furnished and thought it might suit his purpose. My inquiries were directed to a particular end, but I failed to achieve it at the time. I had theories, as I have said, and when, having paid the deposit and secured possession of the keys, I was enabled to visit the place alone, I was fortunate enough to obtain evidence to show that my imagination had not misled me.
"You were very curious the other morning, I recall, respecting my object in borrowing a large brace-and-bit. My object, Petrie, was to bore a series of holes in the wainscoting of various rooms at The Gables—in inconspicuous positions, of course...."
"But, my dear Smith!" I cried, "you are merely adding to my mystification."
He stood up and began to pace the room in his restless fashion.
"I had cross-examined Weymouth closely regarding the phenomenon of the bell-ringing, and an exhaustive search of the premises led to the discovery that the house was in such excellent condition that, from ground-floor to attic, there was not a solitary crevice large enough to admit of the passage of a mouse."
I suppose I must have been staring very foolishly indeed, for Nayland Smith burst into one of his sudden laughs.
"A mouse, I said, Petrie!" he cried. "With the brace-and-bit I rectified that matter. I made the holes I have mentioned, and before each I set a trap baited with a piece of succulent, toasted cheese. Just open that grip!"