and under many thrilling conditions. As a result, he was generally looked up to as a leader by the others, although it must be admitted that Adrian was also a lad of sense and plenty of nerve.

Adrian was the owner of a large Wyoming ranch, and one of the books which has proved most interesting to American boys is known as The Broncho Rider Boys on the Wyoming Trail, a story of how Adrian saved his property from being taken away from him by a dishonest uncle.

About a year previous to the time this story opens, these three boys had been on a trip along the Rio Grande, when they fell in with Capt. June Peak and a company of Texas Rangers, who had been detailed to keep watch of the actions of a band of cattle smugglers. Sent across the river into Mexican territory on a secret mission, the Broncho Rider Boys had the good fortune to rescue Pedro Sanchez, the fourth member of the quartette, from the hands of a band of ruffians. Pedro turned out to be the son of Gen. Sanchez of the Mexican army, who was visiting an uncle in northern Mexico. After a series of thrilling adventures, which are told in full in The Broncho Rider Boys with the Texas Rangers, Donald, Adrian and Billie returned to their homes, promising to visit Pedro in the City of Mexico whenever the time was ripe.

During the time that the boys were scouting in Mexico they had learned to speak Spanish quite well, and this knowledge had been so improved during their visit with Pedro that they now spoke the language well, an accomplishment which proved of much value to them later on.

About a month prior to the day upon which this story opens, the three Americans had met by appointment at New York City and had come to Vera Cruz by boat and thence to the City of Mexico, where they found everything in a greatly disturbed condition because of the revolution which had been started some months previous by Gen. Carranza.

It might be well right here to state briefly the history of the previous few months in Mexico, so that all may understand how it happened that none of the four boys had a very high opinion of Gen. Huerta, at that time dictator of Mexico.

For nearly 35 years, up to 1911, Mexico had a peaceful existence under a republican form of government. During the last 32 years of that time Porfirio Diaz was president. Just prior to 1912 a revolution was begun against what had come to be called the Diaz government, and Diaz was compelled to flee from Mexico. The revolution was headed by Francisco Madero, who was then made president.

In February of 1913 a revolution was started against President Madero by Felix Diaz, nephew of Porfirio Diaz, and the City of Mexico was attacked. At that time Gen. Huerta was in command of Madero's forces in the City of Mexico. He proved a traitor to Madero, went over to Diaz, arrested Madero and confined him in prison. Two days later, April 22, 1913, President Madero was shot by order of Huerta, who then declared himself dictator. At the same time he asked that the other nations of the earth recognize him as the head of the Mexican government, a thing which the government of the United States refused to do.

March 26, 1913, another revolution was started, this time against Gen. Huerta by Gen. Carranza, governor of the state of Chihuahua. This revolution had been in progress more than a year when this story opens.

Pedro's father, Gen. Sanchez, had been a friend of President Madero. When Madero was shot, Gen. Sanchez fled to Pachuca where he had a large hacienda and also owned vast interests in the silver mines at Real del Monte, some six miles up the mountains. Later, however, he was promised protection by Gen. Huerta, who was anxious to have the friendship of such a prominent man, and returned to the City of Mexico. It was some time after this, about March 1, 1914—when matters had quieted down in the City of Mexico—that the three American boys went to visit Pedro.

A few days previous to the one on which we find the four boys headed for the railroad to foil the would-be train robbers, they had come to Pachuca, which is located some sixty miles from the City of Mexico, on horses furnished them by Gen. Sanchez, to see the mines and the beautiful mountains overlooking the plains of Quesco. Every day they took long rides in various directions, in spite of the unsettled condition of the country—a condition which compelled them always to go armed with their trusty Marlins and Colts—and that is how they happened to be on the Real road at such an opportune time.

With these explanations, it is no wonder that the boys were keen for the adventure upon which they were now embarked.

A sharp ride of fifteen minutes brought them to the river and into it the horses plunged. At places it was only knee deep and at other places where they were obliged to cross it was necessary for the horses to swim; but this was only fun for the Broncho Rider Boys.

Half an hour after sighting the bandits, the boys halted on the railroad track, well secreted from their quarry by the curve before mentioned.

"And none too soon," declared Donald as the sharp whistle of the engine was heard perhaps half a mile away.

"How shall we flag her?" asked Pedro.

"With that red bandana handkerchief on Billie's neck," replied Donald as he reached over and snatched the neckwear from its place.

Springing from his horse, he ran up the track waving the red signal as he ran.

A sharp blast from the whistle a couple of minutes later gave proof that the danger signal had been seen, and the grinding of the brakes told that the train was coming to a stop. Even before this was an accomplished fact the conductor swung himself from the front car and came running down the track to see what was the matter, while the guards covered the boys with their carbines.

"What do you mean by stopping the train?" he demanded angrily.

Donald explained in as few words as possible.

The conductor signalled the guards to him and told them what Donald had said.

"What had we better do?" asked the conductor.

"We had better go back to Pachuca for help," replied the guards.

"And let the Zapatistas escape!" exclaimed Billie hotly. "What do you want to do that for?"

"We have only six guards," the conductor explained, "and——"

"And that, with us, makes ten," interrupted Billie.

The conductor regarded the boy with surprise.

"Do you mean you will join us to help capture the bandits?"

"What do you think we're here for?" asked Billie.

"Yes," chimed in Adrian. "What do you suppose we stopped the train for?"

"But even ten are no match for twenty or more," declared the guard.

"Of course they are," said Donald, "if the twenty are taken by surprise."

"Which they will not be if we don't act pretty quick," insisted Billie. "Come on! Let's go after them," and he climbed up onto the car.

"That's what I say," said Pedro, following Billie's example.

Without more words the others followed and the conductor gave the signal to go ahead.

"How about the horses?" asked Donald, turning to Pedro.

"They'll be all right; but if we capture the Zapatistas we'll have horses enough any way."

"And if we don't," remarked Billie grimly, "there'll be some riderless horses any way."

"Let us hope that they will not be the ones we have left behind," said Donald gravely.

CHAPTER II.

A STRANGE MIX-UP.

While the train was gathering headway the conductor and the guards rounded up all the men they could find on the train who were armed. There were more