As the horses galloped over the rolling plains into the darkness of the south, the boys were thrilled by a glow of excitement.  Each had his rifle hanging in a gun-boat from his saddle.  The mystery of the night; the fresh, keen stirring of the September air; the spirit of adventure; the easy, swinging motion of the horses—­all these made the night’s hours worth living for.

For a while, by the moon’s light, Injun had easily been able to follow the tracks of the horses of the three men, and as they continued toward the south, Whitey felt sure that he had guessed correctly, so the horses were urged to a swifter pace.  Little urging was necessary, however, as Whitey’s “Monty” pony and Injun’s pinto were fresh and seemed as eager for the chase as their masters.

Whitey’s plan for thwarting the bandits was simple.  Before reaching the Junction, the boys were to branch off toward the east and intercept the train.  They could stand on the track and swing a lantern, which Injun carried for the purpose.  When the train came to a standstill, they could get aboard, and warn the train crew.  It would be easy to recruit an armed force from among the passengers, for in those days, in the West, there were few men who went unarmed.  And when the bandits attempted their hold-up, they would meet with a warm reception.

The train left the Junction at six, and should reach the water tank about three-quarters of an hour later, though it often was late.  As the boys had started from the ranch house at two, Whitey figured that they would have time enough, though none to waste.

The hours could not be counted, but perhaps three had passed, and through the scented, velvety darkness there came a touch of gray in the east, which changed to pink, then to opal, as the coming sun tinged the low-lying clouds.  The animal and bird life began to stir, preparing to greet the beauty of the dawn, or rather, to start on their affairs of the day, for it is likely that the denizens of the prairie had as little thought for the glory of the sunrise as had Injun and Whitey, whose minds were firmly fixed on train robbers.

When the light was full, the boys drew up, and looked off toward the southwest.  Whitey had been depending on Injun’s never-failing sense of direction to carry them aright.  This ability to point toward any point of the compass, in the dark, was one of Injun’s gifts—­though he didn’t know what a compass was.  And sure enough, away off there against the gray of the clouds was a line of high, tiny crosses, telegraph poles, near which stretched the tracks of the road.

When he saw them, Whitey could not resist a whoop of joy.  “If we ride straight for them, how far do you think we’ll be from the water tank?” he asked.

“Mebbe one mile, mebbe two,” replied Injun, who seldom committed himself to an exact answer.

“That’s all right, come on!” cried Whitey, and they galloped straight for the railroad.