The officer shook his head.

“It would be useless now. We have scattered them and let us hope that we have heard the last of them. It will be my duty, however, to keep a constant lookout for them.”

To the boys’ delight, their stolen stock was all there, too. Firewater whinnied delightedly as he saw his young master, and even the burros seemed to take part in the general rejoicing. While the brigands had made some inroads on the boys’ provisions, there still remained enough food to last them, with care, on the remainder of their dash for the Trembling Mountain.

After the tension of the last few hours it was delightful to feel a sense of security once more. Their enemies were scattered and it was unlikely that the band would attempt any more high-handed methods. Should they do so, however, it would be too late, for before they set forward on the last stage of their journey the adventurers arranged with the captain to meet him and his Rangers at a spot near the Trembling Mountain in three days’ time.

The young officer willingly agreed, but expressed some curiosity as to the nature of their quest. He was informed that the object of the expedition was a scientific one, to investigate the reports of the relics of a forgotten race that lay within the bowels of the mountain.

Jack parted with the Rangers with regret. He had come to admire them for their dash, courage and resource. They were ideal troops for the rough country they patrolled and kept in order by rough and ready methods. The young officer, too, felt much regard for Senor Jack, as he called him.

So a few hours after the reunion in the outlaws’ abandoned camp, the two parties set out in different directions. The Rangers followed the course they assumed that Ramon had taken in his flight, while our adventurers struck out for the smoking peaks which were now much nearer than when they had had their first sight of them. They traveled the rest of that day at a good speed, and sunset found them camped in a pleasant little valley where the broad-fronded banana tree grew, whose fruit afforded a welcome addition to their menu.

The next day, at noon, the professor, after making an observation, announced that they were then within a few hours’ travel of the Trembling Mountain. This announcement was, in fact, hardly necessary, for all day a mighty peak, from whose snow-covered summit there issued a lazy roll of smoke, had overshadowed their way. Everybody guessed that the frowning acclivity was the mountain for which they had come so far in quest.

Late afternoon brought them to its base, and with his measuring instruments the professor, an hour after camp had been pitched, located the entrance which no other American, assuredly, had ever passed. Their pulses beat swift and hard, as the lads and Coyote followed the old man over the rock-strewn slopes to the spot.

Amid a grove of dark, sombre trees,—somehow suggesting a sacrificial grove,—lay the entrance to the Trembling Mountain. All felt a sense of mystical awe as they stood in the solemn shadows. It was as if they had come under the spell of some tremendous brooding presence. Quite unconsciously they spoke in whispers.