CHAPTER XX--A MIDNIGHT ALARM

  As Chet surmised, the timber was open, with a good sod and littlerubbish or shrubbery. None of the bushes was big enough to hide thebuffaloes even at a distance.

  Not an object moved under the trees as the boys pressed on their tiredmounts. If the herd of buffaloes had come this way it had not stopped tograze in the shelter of the timber.

  And that fact puzzled Chet Havens and caused much disappointment to hischum, Dig Fordham.

  "It gets me!" grumbled the latter. "You figured the thing out all right,Chet. We sneaked around and came up behind them all according toprogramme. But plague it all; somebody's removed the buffaloes. They_ought_ to have stopped here."

  "Maybe they kept on to water," said Chet ruminatively.

  "Whew! That wouldn't be a bad idea for us! Where do you suppose wateris? The last drop dribbled out of my canteen two hours ago."

  "Water's right under our feet, I suppose. See how thrifty these treesare. But we can't stop to dig for it," said Chet. "We'd better let thehorses find it."

  "And give up hunting the buffaloes?"

  "For to-night. We don't know how far away our camping place is--andnight is coming fast. The horses have travelled hard."

  "Right!" agreed Dig. "But I hate to give over the hunt."

  "We'll see what the morning brings forth," Chet said cheerfully. "Let'sgive the nags a free rein. Get on, Hero!"

  The bay and the black horse were both thirsty. The boys could see nostream; but their mounts unerringly knew the direction of the nearestwater. Both horses were range born and had run wild as colts. Theinstinct of their ancestors, the pure-blooded mustangs, was strong inthem.

  They struck almost directly northward through the timber and came outinto the darkening plain on the other side. Night was coming fast andthe boys naturally grew anxious.

  They were not exactly lost. Chet had his compass, and, moreover, theycould tell the general direction easily enough by the setting sun. Butthe Grub Stake trail was a long way behind them and all this country tothe west, north, and east was entirely strange to the trail boys.

  "Those buffaloes have plenty of country to hide in," complained Dig, asthe horses plodded on. "No wonder we didn't find them. Whew! this is abig state, Chet."

  "We can pick up their trail in the morning if we want to," returned hischum, smiling.

  "How?" demanded Dig, interested.

  "Why, all we need do," Chet explained, "is to go back to those mounds,find the trail of the buffaloes, and follow it. They left a trace that ablind man could scarcely miss to the point where we turned west. It'seasy."

  "Whew!" blew Dig. "Of course! What a thickhead I am! We'll get thosebuffaloes yet."

  "I don't know," Chet returned thoughtfully. "Ought we to go so far fromthe Grub Stake trail? Father did not tell me to hasten; but I am sure heexpected us not to delay much on the road. I'll feel a whole lot better,too, when I've attended to these deeds," and he patted his breast tomake sure of the packet he carried.

  "Surely you wouldn't drop the chase when we're so near those beasts?"cried Dig.

  "We don't know how near they are. Maybe they're running yet," returnedChet grimly.

  Their mounts quickened their pace and the boys fell silent. Twilight hadfallen, and the immensity of the plains and their loneliness impressedthe lads. Suddenly Chet started upright in his saddle and pointed ahead.

  "Look!" he cried.

  It was the gleam of water. There was no mistaking it. The horses snortedand broke into a trot. It was a fair-sized sheet of water, lying in alittle saucer scooped in the plain--a "water-hole" in the West, but whatwould have been called a "frog-pond" in the East.

  Rushes and willows grew about it. There were several stunted trees, too,offering plenty of firewood if not much shelter. The stars were alreadyappearing in the arch of the sky overhead, and that would be theirtent-roof.

  The two chums became cheerful, however, as soon as they saw water andfuel. An open camp on a fair night like this had no terrors for them.

  They unsaddled their mounts, let them drink their fill, and then hobbledthem on a flat piece of prairie next to the camp. The fire was built andthe strips of venison toasted. They were ravenously hungry and theremainder of the haunch the robber had left for them now looked verysmall. There was no more hard-bread.

  "Whew!" sighed Digby, "I reckon we'll have to start for Grub Stakebright and early in the morning, for we haven't anything to eat!"

  "We still have coffee, and milk for it, and all these cooking things,"chuckled Chet. "Lots better off than many hunters. Lost all your desireto shoot a buffalo, Dig?"

  "Shooting a buffalo is all right, I don't doubt," returned his chumscornfully, "but chasing all over this country hunting the creaturesisn't much fun. Say, Chet!"

  "Put a name to it."

  "What do you suppose ever scared that wolf so?"

  "The wolf that stampeded the buffaloes?"

  "Yes."

  "You may have three guesses. But that's why we're going to keep watchand watch to-night," Chet said grimly.

  "You don't think it was another hunting party?" cried Dig.

  "I believe nothing but human beings would have so scared that greyrascal. My! how he ran! I didn't think of it at the time. I was tooexcited," Chet said reflectively. "But take it from me, boy, that wolfwas running from man."

  "I don't understand it," declared Dig. "If there had been another partybesides us stalking that herd, why didn't we see them?"

  "They wouldn't have been very good hunters if we had seen them," laughedChet.

  "I mean after the buffaloes were stampeded. They must have been in thatthicket out of which the wolf came."

  "Sure. And the very fact we didn't see them after the stampede, makes mesuspicious," Chet returned. "I tell you, Dig, that party that stopped onthe trail and robbed us last night puzzles me greatly."

  "How so?"

  "They left the trail somewhere this side of our last camp; but Icouldn't see where. They were careful to hide their tracks."

  "I reckon, considering that they had robbed us."

  "Well, that might be so, too," ruminated Chet. He did not want tofrighten his chum regarding Tony Traddles and the strange man whomAmoshee had said were on the trail behind them. Yet the thought of thepair of rascals stuck in Chet's mind and dove-tailed into the mystery ofthe two who had stopped to rob their camp.

  "Well," Dig said finally, "I suppose we'll have to do as you say--keepwatch. But we haven't seen anything of any prowlers and it is likelythose fellows who troubled us before are a long way from here."

  "Hope so," agreed Chet. "But we'd better be sure than sorry."

  The boys were tired after the activities of the day; but Dig insistedupon standing the first watch. "And believe me!" he said, "I shall marchup and down all the time. No sleeping on post this trick!"

  Thus dividing the vigil, Chet bade him good-night and rolled up in hisblanket. It was a warm night, however, and later, after he was deadasleep, the boy kicked the blanket off.

  Dig kept away from him, however. There was no sound of roaming animalsof any kind at first, and the watchman did not consider it necessary tofeed the dying fire. The stars rendered a faint light and he could seeobjects in outline quite plainly.

  The horses fed near the camp, and the ripping sound of the grass astheir strong teeth severed it from the roots was the only sound Digapprehended for some time.

  It was as quiet here at this water-hole in the great plain as it wouldhave been in Dig's back yard. There was not even the rustle of a breezein the brakes.

  Dig tramped back and forth along the edge of the pool, occasionallystooping down to peer through the dusk at the horses. He could see thembetter that way. He kept away from his sleeping chum and their outfitpurposely. He did not propose to rouse Chet until it was full midnight.

  He grew thirsty and started to kneel down by the side of the pool todrink. Then he remembered that the horses had quenched thei
r thirst onthis side of the water-hole, and the water was likely to be roiled andmuddy. So he started around toward the other side.

  The water-hole was twenty yards across and its edge was screened bybushes and brakes for most of the way. Dig looked for an opening wherehe could kneel and reach the water, intending to fill his canteen andbring it back with him to the camp.

  Poke stamped and whinnied; but Dig did not hear his mount. He kept onuntil he was fully half way around the water-hole. The plain seemedquite as silent and deserted as before. He could not see the spot wherehis chum lay nor even the gleam of the firelight now.

  Chet was quite given up to sleep. He lay on his back with the neck ofhis shirt open.

  He did not hear the restlessness of the horses, nor any other soundabout the camp. Not at first, at least. But when a rifle explodedsomewhere near, Chet Havens awoke with a start.

  "Hi! what's that?" he ejaculated, and sat up suddenly, throwing off thefinal restraining folds of the blanket.

  "Dig! where are you?" he added and, getting no answer, he scrambled tohis feet and picked up his own rifle that had been lying partly underhim.

  His chum was nowhere to be seen. He shouted again: "Dig! Dig!" and thenstrained his ear to catch the reply. But there was no immediate answerand Chet found himself shaking with apprehension. What had become of hischum?