, or to
where they have planted a mine--they spoke of a fuse----"

"You've got to take chances in times like these!" declared Old Billee.
"I guess if they went down it will suit us."

"Unless they can close it up, or turn water in," suggested Snake,
dubiously.

"Git out! I'm going down!" stoutly declared the rather fleshy veteran
cow puncher, and when he let himself down the hole the others followed.

There was a natural stairway, or what served the same purpose, leading
down out of the stone room where the conspirators had been evidently
plotting so far underground. The passage went down, at first, like a
flight of steep, cellar stairs. Then it straightened out, and, after
twists and turns, led upward.

"Where are we going?" asked Nort.

"Nobody knows!" grimly answered Bud. "But it's safe so far!"

"And we're right on their trail!" added Snake.

"How do you know?" asked Billee.

For answer Snake paused and pointed to a smouldering cigarette stub on
the rocky floor of the passage that had led out of the conspirators'
niche.

"That wasn't dropped many minutes ago," declared the cowboy. "They
came along here."

This was evident, but it was also evident that Del Pinzo and his
conspirators were sufficiently in advance to escape. For, with another
sudden turn, the passage led to another natural, rocky stairway, and
when this had been mounted the boy ranchers found themselves again in
the main tunnel.

"What's this?" cried Bud, when it was evident that they had come back
to the place whence they had started, but farther on, and nearer to the
river end of the tunnel. "This is a regular maze!"

"But where is Del Pinzo?" asked Dick.

"Out there, I fancy," and Nort pointed to where the main tunnel
extended under the mountain and beyond, to the dam in Pocut River.
"They've gotten away!"

"And about time, too!" added Snake, "or they'd be trapped as we may be!"

"Trapped!" cried Old Billee. "What do you mean?"

"I mean there's a mine set here, somewhere! Don't you smell powder
smoke?"

A sharp, acrid odor, once smelled never forgotten, came to the nostrils
of all as they stood there in the tunnel, while the stream flowed
beside them. Whatever the conspirators had done, they had, evidently,
not shut off all the water.

"There it is!" cried Dick, and he pointed to where, in the light of the
lanterns, there could be seen, slowly ascending, a thin wisp of smoke.

"Look out!" yelled Old Billee as Dick