e from the
river," suggested Nort.

"You call up," begged Bud. "I'm going to get ready for this
expedition. We'll have to start in the dark," he went on, referring to
the black tunnel that stretched under Snake Mountain. "But we may come
out into the light. Anyhow, we're going in!"

CHAPTER XX

INTO THE DEPTHS

Preparations for exploring the mysterious tunnel on this occasion were
much more complete and elaborate than when Bud, Dick and Nort walked
through it before. And they did not rush off in haste, the moment it
was discovered that the water no longer came through the reservoir end
of the pipe line that formed the beginning and end of the old
underground stream course.

"There's water enough for nearly a week, anyhow," said Bud, in
discussing their plans. "And if we can't discover the cause of the
stoppage inside of that time, and get it turned on again, we may as
well know that and give up Flume Valley as a bad job."

"That's right," chimed in Nort.

"The stoppage is inside the tunnel, that's sure," voiced Dick.

"Yes," answered his cousin. "The water is running in all right from
the river."

This fact had been ascertained by telephone. The water was running
freely from Pocut River above the dam, and into the pipe that entered
the side of the mountain.

Bud's father had been told of the situation, which followed so closely
on the heels of the discovery of the evil acts of Pocut Pete.

"Doesn't this sort of set you fellows back so you want to give up
ranching?" Mr. Merkel asked his son and nephews.

"Not a bit!" promptly answered Bud.

"We're going to stick!" added Nort.

"And find out what makes this water stop," contributed Dick. "We'll
show up Hank Fisher, Del Pinzo and that other bunch of crooks, too!"

"I don't see how Hank could have had anything to do with this water
stoppage," said Mr. Merkel. "Of course it may develop that he hired
Pocut Pete to infect our cattle, but even that is doubtful. Those
fellows are pretty cute. Anyhow, Pocut Pete is where he can't do any
harm for some time. He won't be tried until fall.

"But it's my idea, boys, that this water stoppage is caused by some
natural means. We are using an old underground river bed, you realize,
and there may be what I'd call a 'hole' in it somewhere. The water
that ought to come to you may drop down that hole."

"But why doesn't it do it all the while?" asked Dick.

"That's one of the mysteries," said his u