passages--good night! That's all I have to say!" and Dick was very
emphatic in this.

"By Zip Foster!" exclaimed Bud, using that expression for the first
time in several days. "You're a cheerful chap to have along on a
picnic like this, Dick! Not!"

"Well, might as well prepare for the worst and hope for the best,"
laughed Dick, while Nort inquired:

"Why don't you tell us more about Zip Foster?"

"Oh--you--say, did you hear anything then?" asked Bud, and his voice
had in it such a note of anxiety that his companions did not, at the
time, imagine he might have been putting them off from a much-wanted
and often-delayed explanation of this mysterious Zip Foster personage.

"Hear what!" asked Dick.

"Something like water running," replied Bud. "I have a notion that our
stream--I call it ours for it doesn't seem to belong to anyone
else--our stream may just trickle off, now and then, into some other
underground course."

"Maybe it does," agreed Dick. "But I don't hear any water running."

"Nor I," added his brother.

"Maybe I was mistaken," Bud admitted. "But I sure would like to come
across that missing water of mine!"

He little realized, nor did the others, what fruit his wish was to
bear, and that very shortly.

"I guess what you heard was the echoes," spoke Dick. "I never heard so
many queer noises."

"It's like the cave of the winds," murmured Nort. "But it's a great
adventure all the same, Bud! I mean it would be great if we didn't
have to worry about the water not coming back," he made haste to add,
for he realized what it would mean to their new ranch in Flume Valley
if no drink could be had for the cattle.

"It beats the finding of the Triceratops all to slathers!" exclaimed
Dick, "and that was no slouch of a happening, either."

"Yes, no telling what's ahead of us," spoke Bud, as he walked along,
unsteadily enough for the way was rough and filled with stones. And,
as the boys tramped along in the tunnel, part of the time in the very
bed of the stream that had gone dry, their lanterns cast fantastic
shadows on the rocky walls. I have said that the stream was dry, but
this was not strictly true, for in places, where the uneven bed formed
depressions, there were pools of water. And, in some places, there
were even little rills trickling along. But they never would reach the
iron pipe that discharged into the reservoir.

On and on tramped the boys, pausing, now and then, to hold up th