No, Ray knew too much of frontier strategy to be so caught. There stood the little grove of dingy green, a prairie fortress, if one knew how to use it. There in the sand of the stream bed, by digging, were they sure to find water for the wounded, if wounded there had to be. There by the aid of a few hastily thrown intrenchments he could have a little plains fort and be ready to repel even an attack in force. Horses could be herded in the depths of the sandy shallows. Men could be distributed in big circle through the trees and along the bank; and, with abundant rations in their haversacks and water to be had for the digging, they could hold out like heroes until relief should come from the south. Obviously, therefore, the cottonwood grove was the place, and thither at thundering charge Field led the foremost line, while Ray waved on the second, all hands cheering with glee at sight of the Sioux darting wildly away up the northward slope. Ten men in line, far extended, were sent right forward half way across the flats, ordered to drive the Indians from the bottom and cripple as many as possible; but, if menaced by superior numbers, to fall back at the gallop, keeping well away from the front of the grove, so that the fire of its garrison might not be "masked." The ten had darted after the scurrying warriors, full half way to the beginning of the slope, and then, just as Ray had predicted, down came a cloud of brilliant foemen, seeking to swallow the little ten alive. Instantly their sergeant leader whirled them about and, pointing the way, led them in wide circle, horses well in hand, back to the dry wash, then down into its sandy depths. Here every trooper sprang from saddle, and with the rein looped on the left arm, and from the shelter of the straight, stiff banks, opened sharp fire on their pursuers, just as Clayton's platoon, dismounting at the grove, sprang to the nearest cover and joined in the fierce clamor of carbines. Racing down the slope at top speed as were the Sioux, they could not all at once check the way of their nimble mounts, and the ardor of the chase had carried them far down to the flats before the fierce crackle began. Then it was thrilling to watch them, veering, circling, sweeping to right or left, ever at furious gallop, throwing their lithe, painted bodies behind their chargers' necks, clinging with one leg and arm, barely showing so much as an eyelid, yet yelping and screeching like so many coyotes, not one of their number coming within four hundred yards of the slender fighting line in the stream bed; some of them, indeed, disdaining to stoop, riding defiantly along the front, firing wildly as they rode, yet surely and gradually guiding their ponies back to the higher ground, back out of harm's way; and, in five minutes from the time they had flashed into view, coming charging over the mile away ridge, not a red warrior was left on the low ground,--only three or four luckless ponies,