head,
"but I'm a bit puzzled. The upper rocks hang over here, and there seems
to be no sign of anything having broken away."

"Let's look in the first cell again," said Chris; "perhaps it begins in
there."

They stepped in to where the ashes lay piled-up and forming a slope on
one side reaching half-way up the back wall, this portion not having
been disturbed.

"No way out of this place except into the next chamber," said Griggs.
"We shall have to look somewhere else. But didn't you say we had found
no weapons yet, sir?" he continued, addressing the doctor.

"Yes; you have not seen any?"

"Looks like a couple of those stone axes yonder," said Griggs, pointing
to the back of the sloping heap. "I'll get them."

He took a couple of steps, and his feet sank in some depth. Then
quickly taking another and another to preserve his equilibrium, he
uttered a cry of annoyance, for his weight had set the whole of the heap
of dust in motion, bringing part into the cell where they stood, while
the rest glided like sand upon a slope, evidently sinking through a
similar opening to that which led into the next chamber, but here formed
in the wall exactly opposite to the window looking out on to the
terrace.

"Lend us a hand," cried Griggs, and he snatched at one of those
stretched out to his aid, following the rest in a hurried flight out of
the place, for the whole of the ashes and bones were in motion and ran
out through the back with a soft rushing sound.

CHAPTER THIRTY SIX.

IT WAS ALL A DREAM.

"Ugh! the dust!" cried Bourne, as they stood together looking back
through what seemed like a mist.

But this soon subsided, and they stepped inside again, to find that a
portion of the heap of remains had glided through an opening at the
back, evidently the way into another cell--one that was dimly lighted
from somewhere above, and which proved as soon as it was examined to be
the way they sought, and not merely a narrow shaft, but a wide opening
going upward and downward, the steps being in the wall which formed the
division between the two chambers.

There was only a narrow landing at the foot of the steps, and below this
the opening seemed to go right down like a square well, into whose
depths the remains that disappeared had glided and lay far below.

"A huge cistern," said Wilton eagerly.

"No," said the doctor; "the old people could not have stored their water
just below the way up to the next range of dwel