"There's a policeman's lantern," panted my companion. "They'll attempt nothing, now!"

I gulped down the stiff brandy-and-soda, then glanced across to where Nayland Smith lay extended in the long, cane chair.

"Perhaps you will explain," I said, "for what purpose you submitted me to that ordeal. If you proposed to correct my skepticism concerning supernatural manifestations, you have succeeded."

"Yes," said my companion, musingly, "they are devilishly clever; but we knew that already."

I stared at him, fatuously.

"Have you ever known me to waste my time when there was important work to do?" he continued. "Do you seriously believe that my ghost-hunting was undertaken for amus.e.m.e.nt? Really, Petrie, although you are very fond of a.s.suring me that I need a holiday, I think the shoe is on the other foot!"

From the pocket of his dressing-gown, he took out a piece of silk fringe which had apparently been torn from a scarf, and rolling it into a ball, tossed it across to me.

"Smell!" he snapped.

I did as he directed--and gave a great start. The silk exhaled a faint perfume, but its effect upon me was as though some one had cried aloud:--

"Karamaneh!"

Beyond doubt the silken fragment had belonged to the beautiful servant of Dr. Fu-Manchu, to the dark-eyed, seductive Karamaneh. Nayland Smith was watching me keenly.

"You recognize it--yes?"

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 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 ident.i.ty, 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 pa.s.sage 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 a.s.sailed 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 white mouse!

"Only one capture!" cried my companion, "showing how well-fed the creatures were. Examine his tail!"

But already I had perceived that to which Smith would draw my attention, and the mystery of the "astral bells" was a mystery no longer. Bound to the little creature's tail, close to the root, with fine soft wire such as is used for making up bouquets, were three tiny silver bells. I looked across at my companion in speechless surprise.

"Almost childish, is it not?" he said; "yet by means of this simple device the Gables has been emptied of occupant after occupant. There was small chance of the trick being detected, for, as I have said, there was absolutely no aperture from roof to bas.e.m.e.nt by means of which one of them could have escaped into the building."

"Then..."

"They were admitted into the wall cavities and the rafters, from some cellar underneath, Petrie, to which, after a brief scamper under the floors and over the ceilings, they instinctively returned for the food they were accustomed to receive, and for which, even had it been possible (which it was not) they had no occasion to forage."

I, too, stood up; for excitement was growing within me. I took up the piece of silk from the table.

"Where did you find this?" I asked, my eyes upon Smith's keen face.

"In a sort of wine cellar, Petrie," he replied, "under the stair. There is no cellar proper to the Gables--at least no such cellar appears in the plans."

"But..."

"But there is one beyond doubt--yes! It must be part of some older building which occupied the site before the Gables was built. One can only surmise that it exists, although such a surmise is a fairly safe one, and the entrance to the subterranean portion of the building is situated beyond doubt in the wine cellar. Of this we have at least two evidences:--the finding of the fragment of silk there, and the fact that in one case at least--as I learned--the light was extinguished in the library unaccountably. This could only have been done in one way: by manipulating the main switch, which is also in the wine cellar."

"But Smith!" I cried, "do you mean that Fu-Manchu..."

Nayland Smith turned in his promenade of the floor, and stared into my eyes.

"I mean that Dr. Fu-Manchu has had a hiding-place under the Gables for an indefinite period!" he replied. "I always suspected that a man of his genius would have a second retreat prepared for him, antic.i.p.ating the event of the first being discovered. Oh! I don't doubt it! The place probably is extensive, and I am almost certain--though the point has to be confirmed--that there is another entrance from the studio further along the road. We know, now, why our recent searchings in the East End have proved futile; why the house in Museum Street was deserted; he has been lying low in this burrow at Hampstead!"

"But the hand, Smith, the luminous hand..."

Nayland Smith laughed shortly.

"Your superst.i.tious fears overcame you to such an extent, Petrie--and I don't wonder at it; the sight was a ghastly one--that probably you don't remember what occurred when you struck out at that same ghostly hand?"

"I seemed to hit something."

"That was why we ran. But I think our retreat had all the appearance of a rout, as I intended that it should. Pardon my playing upon your very natural fears, old man, but you could not have simulated panic half so naturally! And if they had suspected that the device was discovered, we might never have quitted the Gables alive. It was touch-and-go for a moment."

"But..."

"Turn out the light!" snapped my companion.

Wondering greatly, I did as he desired. I turned out the light... and in the darkness of my own study I saw a fiery fist being shaken at me threateningly!... The bones were distinctly visible, and the luminosity of the flesh was truly ghastly.

"Turn on the light, again!" cried Smith.

Deeply mystified, I did so... and my friend tossed a little electric pocket-lamp on to the writing-table.