of Yellin' Kid.

"There may be a flood here!" added Old Billee.

"Can't we get those rascals?" cried Snake Purdee. "I'd 'a' had th'
drop on 'em in another second if they hadn't doused that glim!"

As he spoke they could all hear the rush of iron-nailed shoes when the
wearers of them scrambled over hard rocks in their effort to escape.

Mingled with that sound was the strange one of rushing water.
Realizing that danger might come to them more through the agency of the
strangely-acting underground stream than from the actions of the
conspirators, Bud and Nort flashed their lanterns on the water-course
behind them and around the bend which they had turned to behold the
strange scene.

"It's going down!" cried Bud, for there was no longer any advantage in
concealment or silence, as long as Del Pinzo and the others had fled.
"It's receding!"

"Just as the other did!" added Dick. "They must have opened a gate
here and let the water out!"

"They've done something!" cried Bud, "and we've got to find out what it
is."

"Did you hear that about a fuse?" demanded Snake. "Maybe they're going
to blow the place up!"

"If they do, and the tunnel caves in, good-bye to my water!" said Bud.

"Yes, and good-night to _us_!" grimly added Old Billee.

"Come on!" cried Yellin' Kid. "Let's see what's up there in that hole
in the wall, anyhow!"

"And have your guns ready!" warned Snake Purdee.

However, as it developed, the weapons were not needed. When the boy
ranchers and their friends managed to scramble up the rocky way, above
and to the right of the second hidden, branching stream, and found
themselves in what was virtually a little natural recess hollowed out
of the rocky wall, they saw that it was deserted.

But there were plain evidences of the fact that the men they had seen
had fled in a hurry, as, indeed, they had practically witnessed.
Playing cards, cigarettes, tobacco and bottles were scattered on a rude
wooden table, and there were several candle-ends stuck in the necks of
flasks. The smell of the extinguished candles was heavy on the air.

"But where did they go?" asked Bud, when a hasty glance around the
rocky room disclosed no occupants.

"What's that?" asked Dick, pointing to what seemed to be a hole in the
floor at one corner.

"It's a passage!" cried Billee, holding his lantern above it. "An' big
enough, even for me! I'm going down!"

"Will it be safe?" asked Nort. "It may lead into the stream