“Do you surrender?”

The Mexican’s reply was to dash back once more. Perhaps he hoped to ride and trample his way through the Rangers. But what desperate thoughts raced through his mind in those last moments we shall never know, for presently, as the Rangers approached, a volley came whizzing about the cornered desperado.

One chance of escape only, had he. On the opposite side of the defile lay a narrow ledge running to the top of the sheer cliff. Could he gain that he might stand a chance of escape. Before they realized what he was about to do, Ramon saw the desperate loophole and gathered his horse for the impossible leap across the chasm.

The gallant black, true as steel to his unworthy master to the last, never faltered. Straight out into the air he shot, while the Border Boys and the Rangers alike sat spellbound by the scene.

The horse’s forefeet touched the opposite ledge, but the hold was too weak. With a shrill whinny of terror, with which mingled a terrible scream from Ramon, the beautiful and gallant animal went crashing backward, down, down into the depths of the abyss,—while the horror-stricken onlookers sat paralyzed in their saddles!

The next day a happy party set out from the region of the mystic caves, carrying a freight of treasure and escorted by the Mexican Rangers, who, by Don Alverado’s wish, were to offer them all the protection possible.

An examination of the caves had shown that the professor’s guess that they had been sealed for all time by the explosion of the natural gases was correct. Beyond the first great chamber the foot of man would never more penetrate.

At evening on the second day of their journey, the roofs of Hermosillo came in sight. And then the captain of the Rangers turned to our party.