“It’s all a matter of practice, I reckon,” said the other. “If you stay out here long, you’ll learn to do the same thing. When your life’s apt to depend on your quick shootin’, you don’t waste any time learnin’ how.”

In addition to riding and shooting, the boys took many flights over the surrounding country, accompanied by Steve or one of the other Rangers who was thoroughly familiar with the country. They soon had acquired a good working knowledge of the surrounding territory, and all felt competent to do useful service if called upon.

Nor was their opportunity long in coming. Early one morning one of the patrol riders came dashing into camp, leaped from his horse, and dashed into Captain Bradley’s bungalow. A border town had been raided by the Mexicans the previous night. The citizens had put up a desperate fight, but they were far outnumbered, and during the battle several were killed. Fires were set at different points, and in the resultant confusion the guerrillas made their escape, taking two girl prisoners with them.

As soon as the camp heard this news, all was bustle and preparation. Word was sent out for the Radio Boys to report at Captain Bradley’s office immediately.

They found the Ranger leader pacing up and down the small room, a grim and relentless expression on his face.

He spoke in curt, incisive tones.

“I want you fellows to locate those desperados and, if possible, find out where they go,” he ordered. “They’ve got a big lead over us, and our chances of catching them on horseback or even with automobiles is small. But with your aeroplane you may be able to succeed where we would not. And above all things, we want to get those two girls back. Let that be your first duty. You can start at once, can’t you?”

“Yes, sir,” said Phil. “We’re ready, and so is the machine.”

“Good!” exclaimed Bradley. “If you travel almost due south, you’ll be the most likely to pick up their trail. Do your best, and luck be with you.”

The boys saluted, and hurried out, breaking into a run as soon as they were in the open.