Out of a cloud of yellow dust, which hung like a saffron curtain against the burning cobalt of the sky, appeared the foremost of a group of riders.

“Here they come! Look out, fellows! Let’s sidetrack ourselves and let the Texas limited go by!”

As he shouted this advice Ralph Stetson, a lad of slightly more delicate build than his youthful companions, swung his wiry little pony in a pivotal sweep, and made as if to retreat.

“Hurry, boys!” he shouted.

But Jack Merrill stood his ground, and Walt Phelps, seeing that the leader of the three Border Boys did not swerve in the face of the onrush, did not budge an inch either. But on the street excitement was rife. Cayuses, hitched to the long, strong hitching racks, or simply left to stand with the reins dropped to the ground over their heads, plunged and squealed. Men ran about and shouted, and even the usually stolid Chinese restaurant keepers and laundry men seemed stirred out of their habitual state of supreme unconcern. As for the Mexican residents of San Mercedes, they merely drew their serapes closer about them and from beneath their broad brimmed, cone–crowned sombreros gazed with a haughty indifference at the group of galloping, shouting horsemen.

As Ralph Stetson cantered off, Jack Merrill backed his pony up to the very edge of the raised wooden sidewalk. The little animal was wildly excited and plunged and whinnied as if it felt the bit and saddle for the first time. But Jack maintained his easy, graceful seat as if he had formed part of the lively little creature he bestrode. Walt Phelps, also undisturbed, controlled his equally restive mount.

“Why don’t we cut and run, too, Jack?” asked Walt, as the hind feet of their ponies rattled on the wooden walk. “Those fellows are taking up the whole street. They’ll run us down.”

“Inasmuch as they are just the men that we are here to meet,” responded Jack, “I propose to stand my ground.”

The Border Boys had arrived in San Mercedes that morning, having ridden from El Chico, the nearest town on the Southern Pacific Railroad. They had come almost directly from a short rest following their exciting adventures across the Mexican Border, as related in “The Border Boys With the Mexican Rangers.” In this book, it will be recalled, they had aided the picturesque mounted police of Mexico in running down a band of desperadoes headed by Black Ramon, a famous Border character.

We first met the boys in the initial book of this series, “The Border Boys on the Trail.” This volume set forth how Jack Merrill, the son of an Arizona rancher, and Ralph Stetson, the rather delicate son of an Eastern Railroad magnate and an old school chum, had shared with Walt Phelps, a cattleman’s son, some astonishing adventures, including much trouble with the hard characters who formed the nucleus of a band of cattle rustlers. They assisted in putting them to rout, but not before they had encountered many stirring adventures in a ruined mission church in Chihuahua used as a gathering place by the band. The treasure they discovered secreted in the catacombs under the ruined edifice had given each boy a substantial little nest egg of his own.