lashed his torch in several directions in the hope of catching
sight of the stream.

"I'm going to climb the rocks," he said, after a pause. "Perhaps there
is another opening behind them."

"Remember what Benson said, and be careful," cautioned his cousin.
"There is no use in taking a risk for nothing."

"Yes, I'll be careful," answered Joe, and crawled forward with care.
Darry held his torch as high up as possible, to light the way.

The youth had advanced a distance of fifty feet when he came to a turn
in the passageway. Here the side walls were not over two yards apart,
while the roof could be touched with ease.

Thinking the walking better at this point, Joe struck out once more. The
flare from his torch showed him something of a chamber ahead, and the
water sounded closer than ever.

But hardly had the lad taken a dozen steps when the smooth rock upon
which he was advancing tilted up, sending him headlong. As he went down
the torch was knocked from his hand. Then he slid forward into the
darkness.

"Help!" he managed to cry. "Help!"

"What's up?" came from Darry, but the words were drowned out in the
crashing of one stone against another. In the meantime Joe had fallen,
he knew not whither. He landed on some soft ground, turned over and slid
along, and then took a second drop. A stone fell beside him and pinned
his jacket to the ground.

For the moment the lad was too dazed and bewildered to do anything but
try to get back his breath. Then, as it gradually dawned upon him that
he was not hurt in the least, he endeavored to arise.

"Fast!" he muttered, and tore his jacket away from under the rock. Then
he turned about, trying to locate his torch. But that was missing, and
all was dark around him.

"I'm in a pickle now," he thought. "I wish I had taken old Benson's
advice and remained around the camp-fire. But who would have imagined
that big rock would play a fellow such a trick? How in the world am I to
get back again?"

From a great distance he could hear Darry shouting to him. He tried to
answer his cousin, but whether or not his voice was heard he could not
tell.

With his hands before him, he moved around, and scarcely had he taken a
dozen steps when he slid down a rocky incline. Here there was water; and
he shivered, thinking he might be dropping into an underground stream
from which there would be no escape. But when a pool was gained it
proved to be but several inches deep.

As Joe stood i