These arrangements were hardly completed before "Billy" Brackett and his party, with the two rescued boys, came flying back, pursued by the entire body of Indians. As the former gained the wagons they faced about, and, with a rattling volley, checked for an instant the further advance of the dusky pony riders.

But those Cheyennes and Arrapahoes and Kiowas and Comanches were not going to let so rich a prize as this wagon-train and all those scalps escape them without at least making a bold try for it. If they could only force the train to go into corral, while it was a mile away from the nearest stream, they would have taken a long step towards its capture.

So they divided into two bands; and, circling around, came swooping down on the train from both sides at once. The Plains Indians are the finest horsemen in the world, and their everyday feats of daring in the saddle would render the performance of the best circus-riders tame by comparison. Now, as the two parties swept obliquely on towards the motionless wagons, with well-ordered ranks, tossing arms, waving plumes and fringes, gaudy with vivid colors, yelling like demons, and sitting their steeds like centaurs, they presented a picture of savage warfare at once brilliant and terrible.

At the flash of the white men's rifles every Indian disappeared as though shot, and the next moment their answering shower of bullets and arrows came from under their horses' necks. The headlong speed was not checked for an instant; but after delivering their volley they circled off beyond rifle-shot for a breathing-spell.

As they did so, the wagon-train moved ahead. A few mules had been killed and more wounded by the Indian volley; but their places were quickly filled from the spare stock. By the time the Indians were ready for their second charge, the train was several hundred yards nearer the coveted water than before.

Again they halted. Again the young engineers, inwardly trembling with excitement, but outwardly as firm as rocks, took their places under and behind the wagons, with their shining rifle-barrels steadily pointed outward. Some of them had been soldiers, while others had encountered Indians before; but to most of them this was the first battle of any kind they had ever seen. But they all knew what their fate would be if overpowered, and they had no idea of letting these Indians get any nearer than within good rifle-shot.

"If you can't see an Indian, aim at the horses!" shouted General Lyle, from his position on horseback midway between the two lines of wagons. "Don't a man of you fire until I give the word, and then give them as many shots as possible while they are within range."

The chief had not the remotest thought of allowing his train to be captured, nor yet of being compelled to corral it before he was ready to do so.

The second charge of the Indians was even bolder than the first, and they were allowed to come much nearer before the order to fire was given. The same manœuvres were repeated as before. One white man, a member of Mr. Hobart's division, was killed outright, and two others were wounded. More mules were killed than before, and more were injured; but still the train moved ahead, and this time its defenders could see the sparkle of water in the river they longed so ardently to reach. How thirsty they were getting, and what dry work fighting was! The wagon mules sniffed the water eagerly, and could hardly be restrained from rushing towards it.

But another charge must be repelled first. This time it was so fierce that the Indians rode straight on in the face of the first and second volleys from the engineers' rifles. When the third, delivered at less than two rods' distance, finally shattered their ranks, and sent them flying across the level bottom-land, they left a dozen wagon mules transfixed with their lances.