Taking a towel with him, the boy hurried off to a mountain rivulet, where he bathed the wounded cheek, holding the wet towel to it to reduce the swelling.

Chancing to look up, he observed the guide, Lige Thomas, standing before him, eyeing him keenly.

"Warm, isn't?" grinned Tad.

"Rather. Put the towel down. I want to look at that cheek."

Tad hesitated, drew the towel away, and gazed back at the guide with a challenge in his eyes.

Lige examined the wound carefully.

"How'd you get it?" he demanded, straightening up.

"Why do you ask that? It's only a scratch."

"Because I want to know. If you do not wish to tell me, of course I shall not press you. However, it will be my duty to call the attention of the Professor to it. You see, I am responsible for you boys while you are up here, and----"

"A stone did it," interrupted Tad, with a touch of stubbornness in his tone.

"A stone?"

"Yes."

"How?"

"Somebody threw it at me."

For a moment the guide gazed at Tad doubtingly.

"I'll tell you all about it," exclaimed Tad impetuously. "But promise me that you won't tell the boys. They'd never cease joking me about it. I'm going back there to-morrow to see if I can find the fellow who shied the rock at me. No; I didn't see him at all. I was sitting with my back to him when he let fly at me. But I pinked him, Mr. Thomas. Believe me, I did----"

"Pinked him?"

"Yes, I let him have an arrow full tilt, and I know it hit him, for he yelled and ran away," explained the boy.

"This matter must be looked into," decided Lige thoughtfully. "It begins to look as if Ben Tackers was right about the gang after all. No; I'll not say anything to the crowd. It would only stir them up. We will visit the cave to-morrow, and, while the others are amusing themselves, you and I will look the ground over a bit. I'll go back now, and you may come along when you get ready."

Tad remained by the stream until he heard the supper call, whereupon he rose slowly and picked his way over the rocks to where the others had a.s.sembled about the table in the gathering twilight.

The boy's appet.i.te, however, had not been affected by the experience through which he had pa.s.sed that afternoon, and he stowed away a hearty meal, after which the evening was spent in listening to stories of the chase related by Lige Thomas.

There being still no sign of Ben Tackers on the following morning, a visit to the cave was decided upon. They reached the place about nine o'clock, guided by Tad, who took them to the hole in the rock at once.

"I guess you boys had better fix up some torches," directed Lige.

"Sometimes there are holes within holes, in these mountains, and we don't want to take a sudden drop down a hundred feet or so. Three torches will be enough to light. You had better take along two or three more in case of need."

Before entering, the guide took the precaution of unslinging his rifle, and, placing the boys behind him with the torches, he entered the cave first. They were obliged to stoop to get through the opening. Once within they followed what appeared to be a pa.s.sage hewn out of the solid rock.

"Ah, here we are!" exclaimed Lige finally, straightening and glancing about him curiously.

They found themselves in a dome-like chamber, from which hung suspended hundreds of stalact.i.tes that threw back the rays of the torches in a thousand sparkling, scintillating points of fire.

The Pony Riders gasped in amazement. Never had any of them seen anything like this.

"Wha--what is it?" breathed Tad Butler.

"Stalact.i.tes," announced the Professor.

"Look like icicles to me. B-r-r-r," shivered Stacy Brown.

"It is a very common thing to find them in caves," added the Professor. "But I never have had the pleasure of observing the formation before."

"I can show you some better than these," stated the guide. "I know of a cave, not so very far from here, that is as big as a church, and a regular picture of one, too."

"Is this the end of the cave?" asked Ned.

"No; there are other pa.s.sages leading further into the mountain, at the other end of the chamber there," replied Lige.

"Are we going to explore them?" inquired Walter.

"Yes; we can go further, if you wish. But you boys must keep a sharp lookout where you are going. Don't fool too much. It's easy to get into trouble here, you know."

While Lige was speaking, Tad had edged cautiously to one side of the chamber, where he had observed what appeared to be a small rock, glistening in the light of the torches. He picked it up, un.o.bserved by the others, and dropped it into his pocket for further observation.

The party then pushed on into the cave, one chamber leading into another, forming a bewildering maze, the brilliant reflections almost blinding them at times, until at last Lige Thomas was forced to admit that he never had quite seen the like of it anywhere else in the Rockies.

"Didn't I tell you I'd show you the biggest thing you ever saw in your life?" glowed Tad Butler.

At that instant a yell of terror from Stacy Brown drew their attention sharply from Tad, their eyes bulging with fear at what they saw before them.

There, sitting on its haunches, paws extended menacingly, showing its teeth as it uttered low, angry growls of protest, was a full-grown black bear.

Tad Butler, indeed, had shown some of them the most surprising things they had ever seen. Yet this was not exactly the surprise he had planned for them, or for himself.

The guide had put his gun down as he entered the chamber, to get one of the stalact.i.tes for Professor Zepplin, who wished to examine it. As a result, Lige was now some twenty-five feet away from his weapon.

At first, with the bright reflection in his eyes, the guide was unable to understand what it was that had caused their sudden fright. Yet the breathless silence about him told him instantly that something serious had happened.

The bear had dropped to all fours and was lumbering straight toward Stacy Brown, who stood fascinated, watching the approach of the hideous object, whose raised upper lip showed a row of white gleaming teeth.

"Look out!" yelled Tad suddenly finding his voice.

"Quick, guide!" begged the Professor, weakly.

"What is it? Where?" snapped Lige, crouching down and shading his eyes to protect them from the glare.

He quickly saw what had caused the startling alarm. He saw too, the hulking beast drawing nearer and nearer to Stacy Brown, and knew that only some sudden shock to his mind would break the spell that seemed to possess the boy at that moment.