"Look here, you fellows," Katz finally blurted out. "I want you to understand that you're getting yourselves into trouble."

"Is that so?" came a hoa.r.s.e and scornful voice from the darkness.

"I'm Detective Katz, of the Chicago force," continued the officer, "and I command you, in the name of the law, to return our weapons and let us depart in peace!"

"And I guess you don't know who we are!" came the voice from inside.

"We're Red Mike of the Gulch and Daring Dan of the Devil's Dip, and we're out for blood! When we're at home in the Bad Lands, we feed on rattlesnakes!"

"Say," Tommy whispered to George, "that ain't so bad, is it? Those fellows know they've got the detectives buffaloed, and they're piling it 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 b.u.m 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 pa.s.sed 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 carca.s.s 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 you two formerly lived," said Will. "For all we know, your father may be hiding there now."

"I know it," replied Chester, "but we came on so fast and in such a state of excitement that we didn't think of doing so."

"Well, we mustn't let the others get too far ahead of us," Will suggested. "They must be quite a ways off now!"

"Don't you think we can do a better job with them out of the way?" asked Chester. "They go roaring along like a herd of elephants."

"I presume we can," replied Will. "Anyway we can make an investigation of our own and then go back to camp. Sandy is alone there with his wounded shoulder, and almost anything is likely to happen."

"We'll go into the cave I spoke about a moment ago," Chester said, "and examine it thoroughly with the searchlights."

"What's the idea of that?" asked Will.

"Well, Tommy and George are in some one of these caves. They may be hiding from us or they may have been captured by the train robbers. If they are hidden away, they're quite likely to be in the large cavern I spoke of. It won't do any harm to look through it."

"Why, that must be the cave where we saw the three men last night!" Will exclaimed. "I have an idea that the three men we saw were the two train robbers and your father."

"That was my idea at the time," the boy replied, "but now I can't quite make up my mind that father would tie up with such a bunch."

"Bless your innocent soul," grinned Will. "Your father couldn't help a.s.sociating with them if they insisted upon it! I can see no reason why they should want to molest him, but one can never account for the mental processes of train robbers."

"I believe this is the same place!" Chester cried as they stepped inside. "You know father often talked about moving to this cave, and I've got an idea that he knows more about the locality than I do."

"In what way?" asked Will.

"Well, I think he found some secret pa.s.sage here. I believe he knows how to enter and leave this cavern without being seen. This whole ridge, you know, is honeycombed with caverns and tunnels. I have been told," the boy continued, "that the gorge and the valley to the east formed the basin for a great lake, hundreds of years ago, and that the water seeped through the limestone rock until there wasn't much left of it in some places. There are certainly plenty of caves here!"

"I should say so!" replied Will turning on his searchlight.

"Look here," Chester went on, "that would be a reason for the train robbers hanging to father, if they found him, wouldn't it?"

"I don't understand," replied Will.

"Why, if father knows a lot of pa.s.sages and hiding places and empty river channels, in this section, he's just the man the train robbers would want to tie to."

"I understand now," Will replied. "And you remember, too," he continued, "how mysteriously the three men disappeared last night? Why, they got out of sight as quickly as if they had been painted on a slate and rubbed out."

"That's a fact!" replied Chester.

"There's one thing about it," Will argued, "the train robbers won't dare to go on into the bad lands, for they have no supplies, and their horses must be about used up. By remaining here, they may be able to steal supplies and, possibly get out to Lander and buy some."