Here comes the march upon India. Kings successively submit. Porus alone dares to resist. With a numerous army he awaits the Macedonian on the Hydaspes. The two armies stand face to face on opposite banks. Then occurs the episode of two youthful Greeks, Nicanor and Symmachus, born the same day, and intimate, like Nisus and Euryalus. Their perilous expedition fails, under the pressure of numbers, and the two friends, cut off and wounded, after prodigies of valor, at last embrace, and die in each other's arms. Then comes the great battle. Porus, vanquished, wounded, and a prisoner, is brought before Alexander. His noble spirit touches the generous heart of the conqueror, who returns to him his dominions, increases them, and places him in the number of friends,-- "Odium clementia vicit." The gates of the East are now open. His movement has the terror of thunder breaking in the middle of the night,-- "Quean sequitur fragor et fractae collisio nubis." A single city arrests the triumphant march. Alexander besieges it, and himself mounts the first to the assault. His men are driven back. Then from the top of the ladder, instead of leaping back, he throws himself into the city, and alone confronts the enemy. Surrounded, belabored, wounded, he is about to perish, when his men, learning his peril, redouble their efforts, burst open the gates, inundate the place, and massacre the inhabitants. After a painful operation, Alexander is restored to his army and to his great plans of conquest. The joy of the soldiers, succeeding their sorrow, is likened to that of sailors, who, after seeing the pilot overboard, and ready to be ingulfed by the raging floods, as Boreas dances, _Borea bacchante_, at last behold him rescued from the abyss and again at the helm. But the army is disturbed by the preparation for distant maritime expeditions. Alexander avows that the world is too small for him; that, when it is all conquered, he will push on to subjugate another universe; that he will lead them to the Antipodes and to another Nature; and that, if they refuse to accompany him, he will go forth alone and offer himself as chief to other people. The army is on fire with this answer, and vow again never to abandon their king. The tenth book is the last. Nature, indignant that a mortal should venture to penetrate her hidden places, suspends her unfinished works, and descends to the world below for succor against the conqueror. Before the gates of Erebus, under the walls of the Stygian city,-- "Ante fores Erebi, Stygiae sub moenibus urbis,"--