Phil heard it almost without noticing, although it was a reply to his own question. Yet it was a name that he was destined soon to recall and never to forget. How often for years and years afterward that name came back to him at night, syllable by syllable and letter by letter! Now he rode on, taking no thought of it, and the little village and hacienda lay behind him, sleeping peacefully in the sun. His attention was for the mountains, because they were now entering the defile, the pass of Angostura, which cuts through the spur thrown out by the Sierra Madre. This is lofty, and the way narrowed fast. Nor did the sunlight fall so plentifully there, and the winds grew colder as they whistled through the pass. After the brilliant opalescent air of the plain, they seemed to be riding in a sort of twilight, and Phil felt his spirits droop. Deeper and deeper they went into the cut. Above him loomed the mountains, dark and menacing. Shrub and dwarfed plants clung here and there in the crannies, but the range was bare, and often it was distorted into strange shapes, sometimes like that of the human countenance. The sky showed in a ribbon above, but it had turned gray, and was somber and depressing. Behind came the long line of the army, the wheels of the artillery clanking over the stones. Once or twice Phil thought he saw figures in sombreros and serapes far up the mountainside, watching them. Mexicans, no doubt, ready to report to Santa Anna the advance of the American army. He expected that some stray shots might be fired down into the pass by these spies or guerillas, but evidently they had other business than merely to annoy, and no bullets came. Phil’s horse stumbled, and the boy saved him from a fall with a quick pull. Arenberg’s horse stumbled, also, and Phil noticed that his own was now walking gingerly over a path of solid but dark stone, corrugated and broken into sharp edges. Well might a horse, even one steel-shod, be careful here! Phil knew it was volcanic rock, lava that had flowed down ages ago from the crests of the peaks about them, once volcanoes but extinct long since.