ould illumine the sky,
followed by the crack and rumble of thunder.

"Say, maybe we had better stay under the trees," suggested Andy.

"Suppose the trees should be struck by lightning?" questioned Jack. "I
think we had better go on, especially if we're anywhere near those caves
Jackson mentioned."

A turn in the defile brought them to something of an open place. Here on
one side the rocks towered fully fifty feet above their heads and at one
point there was an opening perhaps fifteen feet square and leading into
the side of the hill.

"This must be the first of the caves!" cried Spouter. "Come on in!" And
without ceremony he led the way, and the others followed, glad to get out
of the storm.

They found the cave an irregular one, running in somewhat of a semicircle
and with a flooring that was comparatively level. It was dry and fairly
comfortable, and once beyond the fury of the storm the lads dismounted
and proceeded to make themselves at home.

The rain continued to come down and, with nothing better to do, the boys
proceeded to make themselves as comfortable as possible. Near the
entrance to the cave they found some leaves and dead tree branches which
were still dry, and these they dragged inside and then made themselves a
campfire.

"I reckon we'll have to cut out going any further," announced Spouter.
"Even if the storm clears away, the trail will be very wet and
slippery."

It still lacked an hour to noon, and with nothing else to do the boys
tethered their horses and then proceeded to investigate their
surroundings. From the campfire they obtained several torches, and with
these in hand they moved along slowly around the bend of the cave and
over a series of rocks which led upward.

"It certainly is a larger cave than I supposed," said Jack, as he and Gif
led the way, with the others close behind.

"I think I see a light ahead, Jack," was Gif's remark. "That must be
another opening to the cave."

"Maybe the two caves that Jackson mentioned are really one, and this
passageway connects them."

"We'll soon find out."

By this time all but one of the torches had burnt themselves out. But
this the lads did not mind, for the light ahead was steadily increasing,
showing that they could not be far from another opening.

"Look!" called Jack suddenly. And then he added: "Keep quiet, all of
you!"

He pointed ahead and there, around a bend of the rocks, all saw two
figures moving around on horseback. On