“Our duty is done, senors,” he said, saluting, “yonder is the end of your journey.”

“One moment,” said Jack, reddening a little and lowering his voice, “here are two letters I will ask you to deliver when you reach Santa Anita once more. And a packet,” he added, handing the officer the articles.

“I shall see that they reach their destination safely,” said the officer, taking them and thrusting them into the bosom of his coat. “And now, adios!”

“Adios!” The cry was caught up by the Rangers and went echoing out along the mountain side.

At the same instant, as though moved by a common impulse, the Mexicans swung their wiry ponies and dashed off toward the East. The Border Boys stood watching them till in a cloud of dust they vanished from their sight forever. Then turning in silence they rode down into Hermosillo. Here telegrams were despatched telling of the success of their quest, and the next day they boarded the train for home. The ponies traveled less luxuriously than their masters, in a stock car, while in the express coach, guarded by shotgun messengers, were the precious trophies of the cave.

“Say, Jack, if I’m not too curious, what was in that package that you handed the officer yesterday?”

The question came from Ralph.

“A present of gems for himself and his men,” was the rejoinder. “I knew you would think I did right in giving it to them. In fact, I had the professor’s permission to do so.”

“And the letters?” asked Ralph.

“Well,” said Jack, “one was to Don Alverado thanking him for all he had done, and bidding him good-bye. The other was to—somebody else.”