"Search me," rejoined Coyote Pete, "but it's some deviltry, you can bet on that--that voice was Ramon's. He's got a plan in his head to get us out of here."

"Well, he'll have a man's-sized job on his hands," rejoined Buck, calmly reloading the magazine of his rifle and running a cleaning rod through the foul barrel.

The others employed their time in the same manner. Thus they waited for what seemed an interminable age. Still there was no sign of the Mexicans. The yard without was empty of life.

"If they don't show up in a few minutes, what say if we open the door and make a rush for it?" asked Jack.

"As good an idea as any," rejoined Buck, "but what I would like to know right now is what they can be doing."

"Queer, ain't it?" said Pete.

They all agreed that it was, but not one could hit upon an explanation that seemed plausible.

Suddenly, Buck, who had been sniffing suspiciously for a few seconds, gave a sharp exclamation.

"Do you fellows smell anything?"

"No----" began Jack, and then:

"Good heavens, yes! Something's on fire!"

"That's right," agreed Pete, without a quaver in his voice. "The varmints hev set fire to the building from the rear."

"That's what!" rejoined Buck, "and we can't get within a mile of them.

I don't suppose there are any rifle holes in the specie room are there, Mr. Geisler?"

"Nodt a vun," rejoined the German, in a peculiar voice, and then they noticed, in the gloomy light of the closed-up place, that his face was ashen white.

It was clear that the German was badly frightened. His knees seemed to be knocking together, in fact. Small wonder, too. The sharp, acrid smell of blazing wood was in the air now. They could hear the crackle of the flames as they devoured the wooden outer walls of the specie room.

"Come, cheer up, my man," Buck admonished the quaking German. "Why you've stood it all through like a major, and----"

"Idt ain't dot. Idt ain't dose mis-er-able creasers dot I'm afraid of," rejoined the German in a quavering voice.

"What then?"

"Dot room behindt us contains, besides der specie, almost a ton of dynamite!"

"Great jumping wildcats!"

The exclamation dropped from Buck's lips. The others were too thunderstruck to utter a word.

"There's only one thing to do," spoke up Pete, his words fairly tumbling out of his mouth in his haste. "We must open the door and, at a signal, make a rush for it. We may never get through, but it's better than being blown up as we shall be if we remain here. The insurrectos must have left their horses somewhere near at hand. Maybe we can find them and escape."

"It's one chance in a thousand!" exclaimed Jack. "But perhaps this will be the thousandth time."

"Let us pray so!" exclaimed the professor fervently.

Buck had sprung to the door. His hand was on the bar. He knew, as did they all, that there was not an instant to lose. Their lives hung by a hair. At any moment the flames might reach the dynamite and then--annihilation, swift and terrible.

"Now!" he cried, dropping the bar. A strange light, not of fear but of determination, gleamed in his eyes.

Clang!

The bar fell to the ground, and the besieged party dashed forth, firing as they emerged.

Suddenly, from without, and just as the insurrectos espied the daring sortie, there came the shrill notes of a bugle. At the same instant a ringing cheer came over the top of the stockade.

What could it all mean? As if in a dream, the boys saw the insurrectos picking up their rifles and rushing toward the gate. But before they could reach it, a glorious sight greeted them.

A regiment of regular Mexican cavalry, the men with their carbines unslung, pouring a disastrous hail into the swarming insurrectos, suddenly swung through the shattered gateway.

Shouts and cries responded everywhere within the stockade. The terrified insurrectos dropped their rifles and ran hither and thither in mad, frenzied panic. It was every one for himself. Over the stockade they clambered, many paying toll with their lives before the carbines of Diaz's troopers.

But in the midst of the turmoil a clear, boyish voice arose.

"Back! Get back, for heaven's sake!"

The officer of the Mexican regulars heard, and wheeled his men. He recognized the thrill of warning in Jack Merrill's tones.

Stumbling forward, the suddenly relieved party of Americans darted toward the gate for their lives. On down the hillside they fled, with the cavalry surging behind and about them.

"What is it? What is the matter?" gasped the officer in English, as Jack stumbled along at his side.

The lad gasped out one word:

"Dynamite!"

Hardly had it fallen from his lips before the ground shook as if convulsed with an earthquake. A red flame shot skyward behind them, and a mighty, reverberating roar went rumbling and echoing over the countryside.

The flames had reached the explosive.

Almost at the same instant a shower of embers, debris, and odds and ends of all descriptions came showering about the retreating force.

Several were cut and bruised by the shower, but none seriously.

Fortunately, also, beyond causing several of the cavalry horses to bolt in mad terror, no damage was done to the troops or our friends. The situation was rapidly explained to the wondering officer whose name was Captain Dominguez, in command of the force detailed to guard the railroad.

"We learned at Rosario that you had come to the mine," he said, in explanation of the troops' opportune arrival, "and, knowing that Madero was in the habit of raiding mines and was in the neighborhood, we made top speed to the rescue."

"And we're all mighty happy to meet you, you kin bet, captain," chimed in Buck, "but ef yer hadn't arrived when you did, we would not have had the pleasure."

"No, I can see that," rejoined the young officer, gazing off down the hillside.

In every direction could be seen Mexican troopers pursuing rebels, shooting them down, without mercy when fight was shown, in other cases, making prisoners. The rout of the insurrectos was complete and final.

Suddenly a figure on horseback was seen coming at a hard gallop toward the little group surrounding Captain Dominguez.

"It's Harding!" gasped Jack, as the figure drew closer, and indeed it was the former West Pointer. But he was in sad case. His shirt was torn almost from his back, his features blackened and seared, and a red stain showed upon his chest.