readers.

In "The Pony Rider Boys in Montana" is told the story of the long and exciting ride over the old Custer Trail, famous in the tragic annals of our earlier days of Indian fighting. Here the boys found themselves drawn into the life of the sheep men, on those great ranges where the sheep men must still defend themselves from the prejudices, and sometimes from the extreme violence, of the cattle men. It was in this connection that Tad Butler and his friends discovered leading clues in the great conspiracy of certain cattle men against the prosperity and safety of the sheep men. This state of affairs led finally to an angry battle, at which the boys were present. Then, too, our readers all recall Tad Butler's capture by the Blackfeet Indians, and all that befell him ere he succeeded in escaping to his friends.

The next stage of adventures took our lads somewhat further east, as told in "The Pony Rider Boys in the Ozarks." It was a thrilling, desperate time when the boys, with their ponies stolen, found themselves facing actual starvation in the wilds. Tad Butler's perilous trip for assistance is bound to bring throbs of recollection to every reader of that volume. The imprisonment of the youngsters in a mine, following a big explosion, formed another interesting scene in the narrative brought forth in that fourth volume of the series. It was here that Chunky, as our readers know, displayed the splendid stuff that lurked under his odd exterior and behind his sometimes queer manners. How, in escaping from the mine, the Pony Rider Boys penetrated a mystery that had disquieted the dwellers near the Ozarks for a long time, was one of the most interesting features of the tale.

But such strenuous life proves the mettle of the right kind of young Americans. So, far from being discouraged, or sighing for the comforts of home, we next find our lads in Nevada, as related in "The Pony Rider Boys on the Alkali." Here they left grass behind for the glaring discomforts of the baked desert lands, where severe thirst was one of the least yet most constant perils. Roving from water hole to water hole, finding them all gone dry, nearly drove the youngsters mad. Then, too, the fight with the mad hermit, who seemed a part of the life of that bleak desert, helped to accustom the boys to the strenuous life of daily danger.

As our readers will recall, it was in the next volume, "The Pony Rider Boys in New Mexico," that the author described the events surrounding the first real acquaintance that our lads formed with the little that is left of the savage Indian to-day. It was here, too, that they beheld the fire dance of the Saboba Indians in all its ancient fury. The adventures of the young horsemen at this point became fast and furious. Between prairie fire and fight they had the most exciting time of their lives.

Later, after a rest at home, as described in "The Pony Rider Boys in the Grand Canyon," the boys visited the wonderful region of the Colorado. Here, as our readers will recollect, the lads were cut off from their trail by the falling of great masses of rock during a fierce storm. Apparently the boys were doomed to remain helpless on a narrow shelf of rock; our readers recall how Tad Butler, at the risk of his life, spent hours in the attempt to get them out of their dangerous situation. The mysterious circumstances that followed the boys all the way along on their journey through the great canyon form a most remarkable series of events.

Now, from Arizona, Tad and his friends had journeyed onward and into the Lone Star State. Here they looked forward only to a long, healthful ride, full of pleasures, yet devoid of anything like sensational excitement. Yet one never knows what the day may bring forth, and these young travelers of ours, though they did not suspect it, were on the threshold of the most exciting experiences that had yet befallen them. The blue mountain ridge in the near distance was teeming with the story that was to unfold before them. So far the ride had been lonely. Of late rarely had they come in sight of a building of any sort, for this part of the state was but sparsely settled. To meet a horseman was an event. In fact they had not met one since the early morning. The Pony Riders had no guide with them on this journey, believing that one would not be needed. Nor did they carry a pack train. One additional pony bore all their extra baggage, each mount being loaded with all that he could carry in addition to its rider. For tents they had brought one large enough to accommodate the entire party. This was in sections, carried on the different ponies.

Five o'clock had come and gone. The sun was partly hidden by the ridge of the Guadalupes towards which the Pony Rider Boys were slowly drawing. Ned called up to the professor who was riding at the head.

"Where are we going to make camp, Professor?"

"Tad will decide that," answered Professor Zepplin without looking back.

"Near a stream, of course," answered Butler.

"Any mosquitoes there?" demanded Stacy.

"No odds, if there are," retorted Ned. "They wouldn't bite you."

"Not if they had got at you first," returned Stacy solemnly. "There's a level place in there by the creek."

"I see it. I'll ride on and have a closer look at it."

Butler spurred his pony ahead of the others. Reaching the foothills of the range he shaded his eyes, gazing up into the cool, green valley or canyon that led into the mountains.

"I guess this will do very well, boys," he said. "I—-"

Bang!

"Wow!"

Stacy with a howl of terror slid from his pony, sending up a little cloud of dust as he collapsed on the plain.

"Wha—-what—-what——-" gasped the professor.

Bang!

Professor Zepplin's sombrero was snipped from his head. Stacy lay groaning on the ground.

"Ride for the rocks!" shouted Tad as shot after shot began popping from somewhere in the mountains, the bullets screaming over their heads close to their ears or snipping up flecks of dust in the plain.

Tad drove his pony straight at Stacy Brown. He scooped the fat boy up by the collar and rode madly for the protection of the rocks, Chunky's heels dragging on the ground. The others rode madly after them, while the shots were still being fired at them. It was an exciting moment. No one knew what the shooting meant, nor did they know whether Stacy really had been hit or not. There was no time to stop to reason the matter out. It was a case of getting to cover as fast as horse-flesh would carry them.

CHAPTER II

A MYSTERIOUS ATTACK

"Pull in close!" cried Tad.

"Where is it coming from?" shouted Ned.

"I don't know. I haven't had time to look. Look out there!"

Professor Zepplin, somewhat slower than the others, had halted a little distance out from the foothills. A bullet threw up a little cloud of dust just to one side of where he was sitting on his pony, followed by a report somewhere up in the mountains.

"Stop that! Stop it, I tell you!" bellowed the professor, waving his sombrero. Almost ere the words were out of his mouth, the sombrero was shot from his hand and went spinning out to the rear. Professor Zepplin did not wait for further parley. He turned his horse, dashing for the protection of the foothills.

In the meantime, Tad Butler had leaped from his pony, placing Stacy on the ground. It was observed that there was blood on the fat boy's left cheek, but his eyes, wide and