"Shoot; shoot," cried Froebel, himself setting the example by firing at a group of shadowy figures that were already on the move. But it was too late; the Indians could be heard scampering away across the prairie. The agent dared not take his men in pursuit, leaving the mules unguarded; but he rode across to the cavalry tents where General Trias and twenty men, who had heard the firing, were already in the saddle. "Fall in with us, then, as you know the direction in which they went," said Trias hurriedly; and away they all galloped. Far away across the plain they could hear the regular beat of the fleeing horses' hoofs. Without stopping, Trias gave the command to fire; the twenty carbines went off like one, and, from the sudden wild screaming ahead of them, Froebel knew that some of the bullets had hit their random mark. This was confirmed in a minute or so when, in the clouded and uncertain light of the moon, he caught sight of three Indians and a horse lying on the ground as the troop swept past. "There they are; load again," shouted Trias; and all could see the feather head-dresses of the Apaches waving in the breeze, still within gunshot. But the next volley took no apparent effect, the shapes were growing dimmer again, and the sounds less distinct. "On; on; we must have them," shouted the General; and, as the horses were tolerably fresh, the task was still not hopeless. "Hark! They have reached the road," cried one of the soldiers, who was perfectly familiar with the neighbourhood. This was the high road to the Texan frontier, in places a mere sand-strip bordered on either side by forests, in others a smooth, well-beaten track bisecting a vast prairie. The news was the reverse of good, for now the Apaches might at any moment separate, and disappear among the trees. The forest part of the road wound very considerably, so that the pursuers would no longer be able to profit by the light of the already setting moon. Half an hour went by; an hour; and still the Mexicans rode on, now certain that they heard the Indians' horses, now equally certain that all of them had dispersed over the prairie or in the woods. But all of a sudden a faint scream sounded along the road, together with the undeniable tramp of horses. The scream came nearer, and the soldiers spurred their breathless chargers round the bend of the road. "There are lights," shouted Froebel. "Yes; carriage-lamps; they have stopped the mail-coach," roared Trias. "Keep it up, my men; we must have them now." "Why, they are running to meet us," said Froebel; "they must have been reinforced." The lights were certainly coming nearer, and, with them, a body of horsemen; and now the soldiers could hear the quick popping of pistol-shots. Then all at once a loud shout arose from where the lights were, the sound of wheels came nearer and nearer, but the accompanying horsemen were obviously riding now in the other direction.