of only one explanation; in short it was fairly evident to
me that the object of the manifestations was to insure 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 wainscoating 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 set a
trap baited with a piece of succulent, toasted cheese. Just open that
grip!"

The light at last was dawning upon my mental darkness, and I pounced
upon the grip, which stood upon a chair near the window, and opened it.
A sickly smell of cooked cheese assailed my nostrils.

"Mind your fingers!" cried Smith; "some of them are still set,
possibly."

Out from the grip I began to take mouse-traps! Two or three of them were
still set but in the case of the greater number the catches had slipped.
Nine I took out and placed upon the table, and all were empty. In
the tenth there crouched, panting, its soft furry body dank with
perspiration, a little