Peggy hastily s.n.a.t.c.hed up the two buckets with which the aeroplane was equipped, and hurried toward the distant figure. She reached Wandering William's side in quicker time than she would have thought possible, such was the stimulating effect of the glad news. The strange "professor" said not a word, but took her by the hand and began striding in great steps across the sandy dunes.

They had walked about a quarter of a mile when they reached a spot where yuccas and p.r.i.c.kly desert plants of different varieties grew thickly. At the bottom of this desolate little valley was a pool on which the sunlight shone glitteringly. It was shallow and warm, and the color of rusty iron, but it was water.

Taking the folding tin cup that Wandering William produced from one of his pockets, the girl drank eagerly. Never had sparkling spring, water in the fruitful Eastern country tasted half so good as that tepid, dirty alkaline stuff that Wandering William had so providentially stumbled upon.

"How did you find it?" gasped Peggy.

Wandering William indicated a tumble down sign post a few paces off.

To it was nailed board with sun faded lettering on it.

"Read it," commanded Wandering William.

"'To the lost in the desert inferno,'" read Peggy, "'water is twenty paces to the west.'"

"If it hadn't been for the white soul of the man who put that up there," commented the "professor," "we might have perished miserably. Heaven bless him, wherever he is."

"Amen," murmured Peggy.

They filled the buckets, and staggering under their weight, Wandering William led the way back to the aeroplane. Roy was awake and thirsty. He drank greedily of the turbid stuff they offered him.

"And now," said the professor, "let's get to work on that radiator."

But try as they would, they could not stop the leak. Indeed, so much water was wasted in their experiments that several more trips to the pool were necessary.

"Looks like we have run into the worst streak of hard luck I ever heard of," sighed Wandering William despairingly, after the failure of the twentieth trial to get the cooling system to hold water.

"We've just got to plug that leak somehow, or--"

He didn't finish the sentence. There was no need for him to do that.

Suddenly Peggy, who had looked up from the baffling task for an instant, gave a cry:

"Look! Look there! What's all that dust?"

"It's hors.e.m.e.n of some kind, and they're coming this way!" cried Wandering William.

As he spoke his hand slid to his hip, and he drew out his well-oiled and worn old forty-four.

"Do you think that they are--that they are Red Bill's men?"

"Don't know yet. The dust's thick and the light's bad."

"If they are?"

"Then we are in for a mighty bad quarter of an hour. Consarn the luck, everything seems to be going wrong at once."

On and on swept the dust cloud, growing close with great rapidity.

With what anxious feelings the strange herb doctor and the girl watched its advance may be imagined. As for Roy, he lay on the floor of the cha.s.sis unaware of what was transpiring without.

There seemed to be several of the riders--a dozen at least.

"What beats me is, if those are Red Bill's men what are they doing in this direction?" said Wandering William, a puzzled look creeping over his weather-beaten countenance.

"Perhaps they have seen that the aeroplane is stranded and are coming to destroy it," hazarded Peggy.

"Maybe," rejoined Wandering William in a far-away voice. His eyes and mind were bent on the approaching cavalcade. If the riders were not Red Bill's men it meant succor and aid. If they were the outlaw's band, it meant-well, Wandering William did not care to dwell upon the thought.

"A few seconds will tell now," he observed as through the dust cloud the outlines of the hors.e.m.e.n became visible.

All at once a shrill series of cries rang out:

"Yip-yip-yip-yee-ee-e-e-e-e-e-e!"

There was something familiar in the sound to Peggy. She leaned forward, straining her ears. Suddenly an active little bronco seemed to separate from the ruck of the riders and dashed forward alone. On his back sat a familiar figure and not a beautiful one, but to Peggy no angel from heavenly regions could have appeared more, beatific just then, for in the rider she had recognized the redoubtable Bud, the leader of the horse hunters.

Bud swept off his sombrero as he dashed up, and was apparently about to make some jocular remark, but he stopped short at the sight of Peggy's pale, anxious face.

"Wa-al, what's all ther trouble hyar?" he demanded; "your sky bronco foundered? Why h.e.l.lo, thar's Wandering William. Didn't know as you was a sky pilot feller?"

"I'm not, I guess," rejoined Wandering William quietly. "I wish I were, and then may be I could help out on this difficulty."

"Wa-al, what's up?" drawled Bud, as his followers came loping up; "anything I kin do? We're on our way back to ther hills frum town,"

he explained. "We caught more than twenty wild horses and took'em inter Blue Creek. One of ther boys sighted you away off or we'd have missed yer I reckin.

"Now, miss, I ain't one ter fergit a blow-out like thet yer gave us at Steer Wells. Jes say ther word an' if you like we'll tow this here cloud clipper back inter town."

"Let's see if we can't hit on a way of fixing it first," said Wandering William; "you see," he explained to Bud, "the radiator--"

"Hyar, hold on thar. Talk United States language. What's wrong with this arrangement meter.

"It's sprung a leak," volunteered Peggy; "look here, you can see for yourself. The hole is tiny, but it's big enough to let out all the water that we need to cool the cylinders."

"Humph," said Bud crossing his hands on the horn of his saddle and gazing abstractedly at the leak, "what you need is solder," he announced presently.

"If we'd had any we'd been out of here long ago," rejoined Peggy, as Roy, hearing the unusual noise, peered over the edge of the cha.s.sis.

"Hullo, kid; what's biting you?" demanded the breezy Bud.

"Guess I'm out of commission for a while," rejoined Roy bravely.

Peggy hastily explained the accident, and then, as she saw no harm in doing so, she gave Bud a hasty sketch of the events leading up to their being marooned on the alkali.

"So you're after that ornery varmint, Red Bill, are yer?" remarked Bud as she concluded; "wa-al I'll do all in my power to help you.

I've bin a studyin' that thar leak while you was a talkite. What you need is suthin' to stop it up."

"Obviously," said Peggy with a trace of annoyance in her tone.

"Now don't git riled, fer I've hit on a scheme ter git yer out of yer troubles."

Bud shoved back his sombrero and gazed triumphantly at the astonished girl aviator.