The ambulance mules, tethered about the tongue, were busily crunching their liberal measure of oats. Each cavalry horse, too, buried his nose deep in the shimmering pile his rider had carefully poured for him upon the dry side of the saddle-blanket. The men were contentedly eating their hard-tack and bacon and drinking their coffee from huge tin cups with the relish of old frontiersmen. One trooper, a few yards away out on the prairie, kept vigilant watch. Pondering deeply over the strange and unaccountable charge that had been laid at his young trumpeter's door, the captain was slowly pacing down the bank, puffing away at the briar root pipe that was the constant companion of his scouting days. Suddenly he heard the sentry call, and, turning, saw him pointing to the ground at his feet.
"What is it, Horton?" he asked, going over toward him.
"Pony tracks, sir. The Indians have been nosing around here since our men left."
There were the prints of some half a dozen little unshod hoofs dotting the sandy hollows in the low ground near the stream, and easily traceable among the clumps of buffalo grass beyond. Charlton could see where they had gathered in one spot, as though their riders were then in consultation, and then scattered once more along the bank. Two hundred yards away stood the lonely log cabin, all that was left of what had been the ranch, and following the trail, the captain presently found himself nearing it. Two tracks seemed to lead straight thither, and before he reached it were joined by several more. Close to the abandoned hut the ground was worn smooth and hard; yet in the hollows were accumulations of dust blown from the roadway up the stream. Around here the pony tracks were thick, and just within the gaping doorway were footprints in the dust—some of spurred bootheels and broad soles, one still more recent of Sioux moccasins. Through the solid log walls two small square windows had been cut and narrow slits for rifles, in the days when the occupants had frequent occasion to defend their prairie castle. The opening to the subterranean "keep" was yawning under the eastern wall, its wooden cover having long since been broken up for fuel. Charlton stood for a moment within the blackened and dusty doorway, and glanced curiously around him.
Except for the new footprints it looked very much as it did when he had first taken occasion to inspect the interior, earlier in the summer. There was nothing left that anyone could carry away, and he wondered why the Indians should have troubled themselves to dismount and prowl about. An Indian hates a house on general principles, and enters one only when he expects to make something by it. Those recent boot-prints, nearly effaced by the moccasins, were doubtless those of some of Blunt's party. Curiosity had prompted some time-killing trooper to stroll out here and take a look at the place. The sunshine streaming in at the open doorway made a brilliant oblong square upon the earthen floor and lighted up the grimy interior. The steps cut down to the dark "dugout" were crumbling away, and it was impossible to see more than a few feet into the passage leading to the underground fortress, where as a final resort in an Indian siege the little garrison could take refuge. A lantern or a candle would show the way, but Charlton had neither. Taking out his match-case, however, he bent down, struck a light, and peered in. Somebody had done the same thing within the last day or two, for there were the stub ends of two matches just like his in the dust at the bottom of the steps, and there, too—yes, he lighted another match and studied it carefully—there was the print of cavalry boots going in and coming out again. Whoever was his predecessor, he had more curiosity than the captain. Charlton had seen prairie "dugout" forts before, and did not care to waste time now.
CHAPTER X.
IN SUSPENSE.
