o find us?" asked Nort, when his own tale, and that of
his brother, had been sufficiently told.

"Well, it was mainly luck, in a way," Bud answered. "After you two
rode off that time, we didn't pay much attention to you for a while, as
we had our hands full with the cattle. Then we didn't worry, even when
it began to get dark, for we figured that the steers had given you more
of a run than usual. We didn't worry, for I told dad that you were
getting to be real ranchers."

Nort and Dick smiled proudly at this tribute.

"But," resumed Bud, "when you fellows didn't come back in the early
hours of the morning, we did begin to get a little leery. And then we
started off to look for you as soon as it was light. We needn't say we
didn't find you. But we kept on hunting, and we were just about to
give up again, and ride off in another direction, when we saw you
heading for us."

"That camp of the professors' is pretty well hidden," spoke Nort. "I
wonder if we can find it again?"

"Bet your boots!" cried Bud. "I could find it in the dark, but we
won't wait until then to close in on the rustlers!"

"That's what they are!" cried Nort "They're cattle rustlers, and
something else! Why, they had the nerve to drive some of our Diamond X
branded cattle right in under our noses, and they never even
apologized!"

"Such fellows don't generally beg your pardon," commented Mr. Merkel,
dryly. "But have you any idea what their game is, boys?" he asked the
two brothers.

"They're digging, blasting and excavating for something that's hidden
in the ground," answered Nort. "Whether it's gold or diamonds I don't
know."

"I don't see how it can be either," said Bud, with a shake of his head.
"Nothing like that has ever been found around here."

"There's always a first time," said Mrs. Merkel, with a smile. "And
wouldn't it be wonderful if there should be a diamond mine on our
ranch? I'd rather it would be diamonds than gold," she went on, "as it
doesn't take so many diamonds to amount to a fortune."

"Well, all I've got to say is that if those rascals rustle off enough
of my steers they'll be making a fortune that I ought to have,"
commented the head of Diamond X ranch. "I think it's time we closed in
on 'em, boys!" he added sharply. "Up to now we didn't have any direct
evidence. But if Nort and Dick saw some of our cattle driven into
their camp, and held there, that's proof enough of what they are."

"That's what I