on. I'll bet if we sat a little nearer, we could hear the detectives'
teeth rattle!"

"The robbers certainly have a sense of humor," grinned George.

In a moment two muscular, bearded figures came out of the cavern and
stood facing the two detectives. The boys at once recognized the men as
the ones who had ridden so fiercely by their campfire on the night of
their arrival. Tommy was certain that one of the men was the person who
had been waiting for supper at the camp when informed of the presence of
the detectives.

"Do you belong with this bunch?" one of them asked.

The boys held up their handcuffed wrists.

"Who's got the key?" demanded the outlaw.

Cullen held out a ring of keys and the robber promptly used one of them
on the handcuff. When the manacles dropped from the boys' wrists, he
threw the ring of keys into the gulch and tossed the handcuffs in the
same direction.

"I've claimed all along that you boys belonged with these train
robbers," Katz gritted as the handcuffs rattled down the slope.

"And now we know it!" Cullen cut in.

The two boys leaned against the north wall of the cavern and shook their
sides with laughter. The fright of the two detectives was so absolute
that it was pitiful.

"You certainly are a bum pair of detectives!" Tommy said.

CHAPTER XV

AN UNDERGROUND CHANNEL

Following along behind the two sheriffs and their deputies, Will and
Chester finally came to the cavern which by mutual consent the boys now
called the Cave of the Three Bears.

"Tommy was headed for this place!" exclaimed Will. "It's a mystery to me
where George disappeared to so suddenly. Of course, we didn't see enough
of his wig-wag to know what he intended to say, but we understand
there's something amiss."

"There are plenty of caverns here in which one may hide," Chester
answered. "There is one just north of this which has several good-sized
rooms. Father and I thought of moving to that one."

They passed into the Cave of the Three Bears and found that one hide had
been partly removed, and that a huge piece of meat had been taken away.

"I guess Tommy's been here all right!" Will suggested.

Chester stooped down and examined the carcass carefully.

"No," he said. "Tommy wanted the three skins for rugs. He never cut the
hide like that to get at the meat."

"No, he wouldn't do that," Will admitted.

"Father may have been here," suggested Chester.

"We should have stopped at the cave where