patch of timber and plunged
beneath the low-drooping trees. Here it was both dark and cool, and
Darry breathed a long sigh of relief.

"How delicious!" he murmured. "It's almost like going into a cave.
Benson, there must be lots of caves in these mountains," he went on
reflectively.

"There are," answered the old scout. "I've been in a score or more."

"I should like to explore a big cave," came from Joe. "It would be a
novelty to me."

"You may get the chance, lad," said Benson; "and get it soon."

"What do you mean? Are we going to ride by a cave?"

"There are a dozen or more ahead, and we may have to seek one of 'em for
shelter. Do you hear that?"

Benson threw back his head to listen, and the two boys did likewise.
From a great distance came the rumble of thunder, echoing and re-echoing
throughout the mountains. To the westward the sun was hidden by a dense
mass of black clouds which grew more ominous each instant.

"The storm is coming, sure enough," muttered Joe. "What do you propose?"

"We'll ride on a bit, lad. It won't hit us right away. Come!"

The horses were urged forward at an increased speed, and soon they
passed the patch of timber and came out to where a thick fringe of brush
skirted a long, high cliff. The sky was now dark on every side, and the
wind was rising with a dull, humming sound.

"We'll catch it in a few minutes!" cried Benson; and hardly had he
spoken when the big drops came splashing down, hitting the broad leaves
in the underbrush with resounding smacks.

The old scout continued to lead, and presently he turned to the left,
where the cliff parted. Here was an opening, lined on either side with
rocks and dirt, and a short distance further was the entrance to a cave
of unknown depths.

"We'll stop here," said the old scout, leaping to the ground, followed
by the boys. "This aint the best place in the world, but it's better
than the open, in such a blow as is coming."

He was right about the blow--already the wind was rising, and hardly had
the three led their horses into the cave, the entrance to which was over
a dozen feet high, when there came a crashing through the timber left
behind, which sent many a frail limb and sapling to the ground and
carried the leaves and twigs in all directions.

"I'm glad we didn't stay in the woods!" cried Darry. "We'd be in danger
of falling trees."

"And lightning too," added Joe. "Oh, my! look at that!" he continued, as
a blinding flash