oncealed.

"Stand back, Kennedy!" he warned.

Kennedy moved on to a lower step--as Smith, bringing all his weight
to bear upon the ring, turned the huge stone slab upon its hidden
pivot, so that it fell back upon the stair with a reverberating boom.

We all pressed forward to peer into the black cavity. Kennedy moving
the light, a square well was revealed, not more than three feet across.
Foot-holes were cut at intervals down the further side.

"H'm!" said Smith--"I was hardly prepared for this. The method of
descent that occurs to me is to lean back against one side and trust
one's weight entirely to the foot-holes on the other. A shaft appeared
in the plan, I remember, but I had formed no theory respecting the
means provided for descending it. Tilt the lamp forward, Kennedy.
Good! I can see the floor of the passage below; only about fifteen
feet or so down."

He stretched his foot across, placed it in the niche and began to
descend.

"Kennedy next!" came his muffled voice, "with the lamp. Its light will
enable you others to see the way."

Down went Kennedy without hesitation, the lamp swung from his right
arm.

"I will bring up the rear," said Sir Lionel Barton.

Whereupon I descended. I had climbed down about half-way when, from
below, came a loud cry, a sound of scuffling, and a savage exclamation
from Smith. Then----

"We're right, Petrie! This passage was recently used by Fu-Manchu!"

I gained the bottom of the well, and found myself standing in the
entrance to an arched passage. Kennedy was directing the light of the
lamp down upon the floor.

"You see, the door was guarded" said Nayland Smith.

"What!"

"Puff adder!" he snapped, and indicated a small snake whose head was
crushed beneath his heel.

Sir Lionel now joined us; and, a silent quartette, we stood staring
from the dead reptile into the damp and evil-smelling tunnel. A
distant muttering and rumbling rolled, echoing awesomely along it.

"For Heaven's sake what was that, sir?" whispered Kennedy.

"It was the thunder," answered Nayland Smith. "The storm is breaking
over the hills. Steady with the lamp, my man."

We had proceeded for some three hundred yards, and, according to my
calculation, were clear of the orchard of Graywater Park and close to
the fringe of trees beyond; I was taking note of the curious old
brickwork of the passage, when--

"Look out, sir!" cried Kennedy--and the light began dancing madly.
"Just under your feet