A great cloud of dust rose from the corral.  The mustang was darting here and there, bucking, squealing and kicking.  In a moment most of the other mustangs were doing likewise.  The owner of the herd, calling to the Professor, darted out, leaving one bar of the fence down.  Professor Zepplin, becoming confused, missed his way and found himself penned into one corner at the far side, almost the center of a circle of kicking mustangs.

Tad saw the danger of their companion almost at once.  The lad leaped down, and darting among the kicking animals, made his way toward the Professor just as Stacy’s mustang leaped the bars.  Stacy’s toes caught the top rail, retarding his progress for the briefest part of a second, then he shot out into the air after the racing mustang.

“Leggo!” roared the boys.

“Let go!” shouted the guide.  “The little fool!  Doesn’t he know enough to come in out of the wet?”

“You’ll find he doesn’t, sir.  Your troubles have only just begun.  You’ll be demanding an increase of wages before you have followed Stacy Brown for a full twenty-four hours,” prophesied Ned.

In the meantime Tad had reached the Professor, regardless of the flying hoofs about him.  With his rope the boy drove the animals off just in time.  Somehow they seemed to have taken it into their heads that the Professor was responsible for their having been disturbed and they were opening their hoof batteries upon him.  They gave way before the resolute young Pony Rider almost at once.  They recognized that this slender young plainsman and mountaineer was unafraid.

The Professor was weak in the knees by the time he had been led out.

“I didn’t know you were in there,” apologized Nance.

“Where’s Stacy?” was the Professor’s first question.

“He’s gone by the air line,” answered Walter.

While all this had been taking place Chunky had continued in his mad flight for a short distance.  He had a long hold on the rope by which the mustang was hauling him.  The wary beast, espying a tree whose limbs hung low, changed his course and darted under the lowest of the limbs.  Its intention was plain to those who knew the habits of these gentle beasts.  The mustang intended to “wipe” the Pony Rider boy free of the line.

Just before reaching the low-hanging limb the pinto darted to one side, then to the other after an almost imperceptible halt.  The result was the rope was drawn under the low limb.  A quick leap on the part of the mustang, that exhibited almost human intelligence by this manoeuvre, caused Chunky to do a picturesque flop over the limb, falling flat on his back on the other side.  This brought the mustang to a quick stop, for the rope had taken a firm hitch around the limb.

The sudden jolt and stoppage of his progress threw the mustang on his nose, where he poised for a few seconds, then he too toppled over on his back.