r 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.

"He was in that explosion, the precious scoundrel!" grated out Buck, as
his eye took in these details. "He was one of the fellers that set
that fire."

Straight for the little party Harding rode. But before he reached them
two Mexican troopers interposed. They raised their carbines and the
next moment would have been Harding's last, but for Jack.

"Don't let them fire!" he begged.

The captain shouted