." And the party passed on, with the sides of the ravine
closing in till the way grew half dark, and as far as they could make
out they were at the mouth of a good-sized cavern.

Here they stopped short, and the doctor held up his hand.

"What is it?" whispered Mark.

"It may be fancy," replied the doctor, "but I fancied I heard a faint
rustling."

This sounded so like a warning to beware of any wild beast which might
be the occupant of the cavern that three of the party cocked their
pieces and waited for the doctor to go on.

"Like me to go first, sir?" said Buck quietly.

"No, I will go on directly, my man; but look here."

Everyone pressed forward to look at that which had taken the doctor's
attention, for he was gazing into a side nook that suggested, from a dry
heap of fern-like growth and grass, that it had lately been occupied.

Bob Bacon pushed past Mark, went down upon one knee, and began feeling
the dry grass. "Well?" said Mark sharply.

"It arn't cold, sir, nor it arn't warm; but I should be ready to say
that something's been lying here not long ago."

"An animal of some kind, then," said the doctor, lowering his rifle.
"You, Bacon, you are a very fair shot; come beside me; but don't fire
unless there is real necessity. You boys, come along cautiously. There
may be a leopard here. Don't fire unless it springs."

"All right, sir," said Mark. "Well, Buck, you can come next."

"Well, no, sir; if you wouldn't mind I think I will walk close to the
doctor. I am big and strong, and I shouldn't like to see you hurt."

"Oh, nonsense!" cried Mark. "I am not going to give up my place, and I
don't believe that there is anything here after all."

"Stop again," said the doctor. "I am sure I heard something moving, and
it's getting quite dark in front. Let's have a light."

"Here you are, sir," cried Buck Denham. "Strike a match, somebody."

This was done, the big driver holding Bob's resinous wood to the flame
till it began to blaze well, and then winking to himself, as Dean saw,
the big fellow stepped right forward before the rest, holding the
improvised torch so that the light illumined the glittering walls and
ceiling of the rift of beautifully clean granite rock.

Everyone was on the alert, as Buck now led on and on into the darkness,
till he said, "You will mind and not shoot me, gen'lemen; but be on the
look out, for there is something here."

The man stopped short as he spoke, holding