How different were the feelings with which I now prosecuted the search. No longer indifferent about the escape of the robbers, I was determined on tracking them up, if I should have to traverse every defile in the Cordillera, or climb to the summit of Popocatepec! Like a second Ordaz, I could have plunged into its fiery crater to rescue the captive, who but a short hour before might have leaped into it, without my stretching forth a hand to restrain her! It was all changed now. The wound, that had been bleeding for six long months, had become suddenly cicatrised. A load seemed lifted from my heart. I felt light and lithe as I sprang up the acclivity. No Alpine climber could have equalled me in energy: for never went one with such a purpose to stimulate his strength. It were a trite triumph to scale the summit of the Matterhorn, compared with that of rescuing Mercedes Villa-Senor! The path was not only difficult, but perilous. It would have been so in the day. At night both the danger and difficulty were doubled. It was all up hill--steep as the side of a cairn, and with footing not much surer. The surface was corrugated with lava runs, that had been liquid some centuries before--now congealed into scoriae that resembled the slag cast forth from a furnace. It was not treeless; but sparsely covered with cactus, grass-like tufts of _zamia_, and stunted fir-trees. Here and there were patches bare and coal-black--as if the lava had but recently cooled, after being vomited forth from the _volcan_ above. Two things greatly delayed us: the darkness, and the necessity of making a noiseless advance. The slightest sound--a word spoken aloud--might frustrate the purpose of our pursuit. I had given strict orders for no one to speak--even in whispers. In these alone the guide conversed, as he gave his directions. We knew that our voices would be carried upward to the ears of the brigands, while there was not much likelihood of our hearing theirs. That they were above us we had little doubt; though we neither heard nor saw them. We were assured by the nature of the ground. The path carried us along the combing of a ridge--on either side flanked by a stupendous precipice. It was but the continuation of the twin cliffs that hemmed in the hacienda below. We saw no side track, that the robbers could have taken. We were certain we had them before us. Our search promised fair for success. The robbers could have no suspicion that they were being followed--least of all by a score of American riflemen. The only enemy they might deem near had been left helpless below. Silently we toiled on, stepping as lightly as possible over the loose lava. At intervals we stopped to listen. We fancied we could hear footsteps and the murmuring of men. We were not sure about either. The torrent tearing along the bottom of the "barranca" sent its "sough" into our ears--filling them to the exclusion of almost every other sound.