He pointed to one, and then another track in the soft sand.  “Maybe that might be a coincidence, but the owner of that horse had a habit of squirting tobacco juice on clean rocks—­like that—­and that.”

“That doesn’t prove he has been rustling.”

“No; but the signs here show he has been branding, and Buck Weaver ran across these same marks left by a waddy who surely was making free with a Twin Star calf.”

“How long has he been gone?”

“There were two of them, and they’ve been gone about twenty minutes.”

“How do you know?”

He pointed to a stain of tobacco juice still moist.

“Who is he?” she asked.

He knew her stanch loyalty to her friends, and Tom Dixon had been a friend till very lately.  He hesitated; then, without answering, made a second thorough examination of the whole ground.

“Come—­if we have any luck, I’ll show him to you,” he said, returning to her.  “But you must do just as I say—­must be under my orders.”

“I will,” she promised.

Forthwith, they started.  After they had ridden in silence for some distance, covering ground fast, they drew to a walk.

“You know by the trail for where they were heading,” she suggested in a voice that was a question.

“I guessed.”

Presently, at the entrance to a little canon, Keller swung down and examined the ground carefully, seemed satisfied, and rode with her into the gully.  But she noticed that now he went cautiously, eyes narrowed and wary, with the hard face and the look of a coiled spring she had seen on him before.  Her heart drummed with excitement.  She was not afraid, but she was fearfully alive.

At the other entrance to the canon, Larrabie was down again for another examination.  What he seemed to find gave him pleasure.

“They’ve separated,” he told Phyllis.  “We’ll give our attention to the gentleman with the calf, and let his friend go, to-day.”

They swung sharply to the north, taking a precipitous trail of shale that Phyllis judged to be a short cut.  It was rough going, but their mountain ponies were good for anything less than a perpendicular wall.  They clambered up and down like cats, as sure-footed as wild goats.

At the summit of the ridge, Keller pointed out something in the valley below—­a rider on horseback, driving a calf.

“There goes Mr. Waddy, as big as coffee.”

“He’s going to swing round the point.  You mean to drop down the hill and cut him off?”

[Illustration:  “DROP THAT GUN!” Page 205]

“That’s the plan.  Better do no more talking after we pass that live oak.  See that little wash?  We’ll drop into it, and hide among the cottonwoods.”

The rustler was pushing along hurriedly, driving the calf at a trot, half the time twisted in the saddle, with anxious eyes to the rear.  Revolvers and a rifle garnished him, but quite plainly they gave him no sense of safety.