r was lost in the
darkness, as a thicker cloud than any that had yet obscured it, covered
the moon.

For several seconds the three boy ranchers remained, looking off in the
gloom which had swallowed up the mysterious scientist. For that he was
mysterious none of the lads could deny.

"Wonder where he had been?" mused Bud in a low voice, for in that
silent, dark open place voices carried almost as clearly as across
water, and he was cautious.

"Search me!" declared Nort.

"Guess he didn't expect to see us," added Dick.

"Say!" suddenly exclaimed Nort, urging his horse against Bud's in his
eagerness and excitement, "maybe he was one of the cattle rustlers,
Bud! He circled around and rode back after he found he couldn't get
away with the steers, and that Babe was on his trail. That's what it
is!"

"No," spoke Bud, quietly. "There's something queer about that
man--Professor Wright as he calls himself--but he isn't the kind that
rustles cattle. Cattle thieves don't make a permanent camp. They're
wanderers--mostly Greasers, Indians and half breeds, with a bad white
man mixing in--and they don't stay long in one place."

"Don't you think he had anything to do with trying to drive off your
cattle?" asked Nort.

"Well, you can't be altogether sure of anything in this world," half
drawled Bud, "but it doesn't seem reasonable."

"But he came from the direction to where those men ran that were
driving away the cattle," said Dick. "Wonder if he met Babe?"

"You can ask him," said Bud. "Here comes Babe now."

The two other lads were not aware of the approach of the assistant
foreman of Diamond X, but Bud's quick ears had caught the faint sound
of the horse's feet approaching, and in another moment Babe rode up
from a little clump of greasewood shrubs, which growth, to the eastern
lads, had resembled sumac at first.

"Find 'em, Babe?" asked Bud in a low voice.

"Nope! They razzled off 'fore I could get up to 'em. All right here?"
he asked, though a look convinced him there had been no serious
trouble, at least.

"All serene," answered Bud. "Did you meet the professor?" he inquired.

"The professor?" Babe's tone of voice, indicating surprise, was answer
enough. But Bud went into particulars, telling how the scientist had
ridden up on them a little while before.

"No, he didn't come nigh me!" declared Babe. "Mighty funny, too," he
went on.

"Could he be one of the rustlers?" asked Nort, eagerly.

"