essly. "We shall presently
find ourselves at the base of the east tower."

Down we went and down, the ray of the electric lamp always showing
more steps ahead, until at last these terminated in a level, arched
passage, curving sharply to the right. Two paces more brought us to a
doorway, less, than four feet high, approached by two wide steps. A
blackened door, having a most cumbersome and complicated lock, showed
in the recess.

Nayland Smith bent and examined the mechanism intently.

"Freshly oiled!" he commented. "You know into whose room it opens?"

Well enough I knew, and, detecting that faint, haunting perfume which
spoke of the dainty personality of Karamaneh, my anger blazed up
anew. Came a faint sound of metal grating upon metal, and Smith pulled
open the door, which turned outward upon the steps, and bent further
forward, sweeping the ray of light about the room beyond.

"Empty, of course!" he muttered. "Now for the base of these damned
nocturnal operations."

He descended the steps and began to flash the light all about the
arched passageway wherein we stood.

"The present dining-room of Graywater Park lies almost due south of
this spot," he mused. "Suppose we try back."

We retraced our steps to the foot of the stair. In the wall on their
left was an opening, low down against the floor and little more than
three feet high; it reminded me of some of the entrances to those
seemingly interminable passages whereby one approaches the sepulchral
chambers of the Egyptian Pyramids.

"Now for it!" snapped Smith. "Follow me closely."

Down he dropped, and, having the lamp thrust out before him, began to
crawl into the tunnel. As his heels disappeared, and only a faint light
outlined the opening, I dropped upon all fours in turn, and began
laboriously to drag myself along behind him. The atmosphere was damp,
chilly, and evil-smelling; therefore, at the end of some ten or twelve
yards of this serpentine crawling, when I saw Smith, ahead of me, to
be standing erect, I uttered a stifled exclamation of relief. The
thought of Karamaneh having been dragged through this noisome hole
was one I dared not dwell upon.

A long, narrow passage now opened up, its end invisible from where we
stood. Smith hurried forward. For the first thirty of forty paces the
roof was formed of massive stone slabs; then its character changed;
the passage became lower, and one was compelled frequently to lower the
head in order to avoid