The party Dorothy Dale and her companions were following into the wilder section of the great Hardin , had almost an hour’s start of their pursuers. If they were ignorant of such pursuit they might not ride at top speed; therefore the pace set by Lance Petterby on his , Gaby, must bring the pursuers to the river at about the time Philo struck it. Only Dorothy and her friends were bound to strike the stream higher up and nearer the point where Lance believed the was to be used by the men working for the big mining corporation.  
The puzzle was how Philo Marsh and his crowd could have traveled as fast as they did, with Mrs. White in the party. Aunt Winnie was a cautious rider and the boys and Dorothy were ever complaining of her slowness when they were all out on the range together.
 
But when the pursuers chanced to cross the trail of the they pursued, the hoofmarks of the showed that they were traveling fast.
“Goodness!” exclaimed Nat. “She never would ride with us faster than a funeral.”
 
“That shows she is forced to keep up with them,” Tavia declared, with conviction.
 
“Don’t talk about it!” Dorothy. “I only hope those awful men can be punished for this.”
 
“Don’t you , Miss Dale,” broke in Lance Petterby, grimly. “If Philo has offered Mrs. White any I dunno but he’ll be hung for it. The boys’ll be sore—believe me!”
 
“That would be dreadful, too,” sighed Dorothy.
 
“Serve him just right, I say!” said Tavia, shortly.
 
This conversation had been carried on while they were mounting the steep rise to the plateau described. In ten minutes they were at the river bank. The ground was of such a nature here that at a casual glance one could not tell whether horsemen had recently passed, going up stream, or not.
 
“Come on!” commanded Lance, waving his hat. “Whether them hombres is thar, or not, we’ll pull a hot finish.”
 
The ponies dashed on, following Gaby, as though fresh. They thundered on up the very narrow trail the girls had followed that day they had climbed to the mountain-top.
 
 Suddenly, in a wide opening of the forest-clad plateau, they caught sight of a number of horsemen ahead. It was Marsh and his companions, but they got out of sight so quickly that Dorothy could not be sure that Aunt Winnie was with them.
 
The cowboys broke into yells of excitement. The ponies dashed forward, and whether the girls would, or no, they were borne at a desperate pace right up the trail after the other flying squadron of horses.
 
“Isn’t it great?” yelled Tavia, as she rode knee to knee with Dorothy.
 
“I think it is dreadful,” Dorothy.
 
But Tavia seemed to be enjoying the race to the full. And it was a race now. Philo Marsh had seen them coming, and without doubt he would try to do what he had to do, and get it over with, before the pursuers overtook him.
 
If the dynamite was ready set, and he could explode it before the pursuers reached the spot, nothing could put Lost River back into its course again.
 
Again and again Dorothy and her companions came in sight of the party ahead, but the glimpses they obtained were for a moment only.
 
“They’ve got some hoss-flesh thar,” commented Lance Petterby. “And they warn’t as fresh in the beginnin’ as ourn—that’s sartain. They230 been punishin’ of ’em some, by Jerusha Juniper!”
 
“I—don’t—see—how—Aunt—ie—can ride so fast!” Dorothy.
 
“She never did before,” repeated Nat.
 
The pursuers had not lost hope. The trail over the plateau was twisted, but almost level. Their horses seemed quite as willing as when they had started from the ranch-house.
 
They dashed up the little rise beside the noisy rapids and then the opened before them for some two miles. Philo Marsh and his crowd were just ahead. The pursuers could see them quite plainly.
 
Lance began to yell and beat his pony with his hat. The Mexicans’ were as as a dog’s howl. The boys and Tavia were caught up by the excitement, and they shouted, too, but Dorothy remained silent.
 
She searched the cavalcade ahead for a glimpse of her aunt’s figure. There was a female in the crowd; but, was it Aunt Winnie?
 
Surely, that good lady could never have ridden with such abandon—not even if she had been to her saddle! And this person ahead wore garments of much more brilliant color than Aunt Winnie had ever been known to put on.
 
“That never in the world is Auntie!” cried Dorothy, at last.
 
Tavia heard her, and flashed her chum a broad231 smile. Then Tavia urged her horse on, shouting as the boys shouted.
 
“You knew it all the time, Tavia Travers!” screamed Dorothy, in anger.
 
She crowded her own pony close to Tavia’s mount and shook that irrepressible young person by the arm. Tavia would pay no attention to her. The end of the race promised to be exciting, and Tavia’s attention would not be aside.
 
They were in sight of the head of the . The men in the lead began to yell. Evidently they expected to find some of their own kind here.
 
One of the Mexicans in the party of pursuit whipped a long-barreled revolver into sight. The herdsmen of Hardin Ranch were not supposed to carry weapons save at night when riding . Lance Petterby saw the gun and yelled at his :
 
“Put away that gat.! I’ll natcher’ly manhandle any feller that fires a gun.”
 
The next moment Ned White uttered a shout. “Hi! that’s not mother with those fellows. It’s—it’s that Mexican girl, Flores!”
 
Only a hundred yards separated the two parties. The girl who had ridden in the midst of the leading crew, suddenly swung her pony to one side, wheeled him about, and dashed back toward Dorothy and her friends.
 
“Flores! Flores!” cried Dorothy.
 “They blow up! They blow up! Dynamite!” Flores, waving her arms excitedly and letting her pony take his course.
 
Some of the Mexicans held in their ponies. At the warning more than one desired to keep out of the danger zone. But Lance Petterby drove on, yelling:
 
“Not much they won’t set off no dynamite. They ain’t gwine tuh be let.”
 
Without doubt he would have flung himself the next minute, single handed, upon the half dozen scoundrels had there not occurred something quite unexpected. Philo Marsh and his henchmen had leaped from their horses. They were almost at the head of the gorge. The rock between where the ground fell away into the , and the of the rushing river, was narrow. It was plain t............