the form of a locomotive trailed by a long line of passenger cars. Across the desert it came, its swift passage now marked by a rumbling roar, and hurling the dust in a long, thin cloud. When the musical tritone of the whistle reached her, Nevada closed her book with a snap and leaned out of the window. In less than a minute Number Seven, with a loud screeching of its brakes, slid to a halt at the water tank. The huge, palpitating locomotive, its air-pump breathing hard, like a hound after a hard chase, halted but a few yards from Nevada’s open window. Out of the cab was thrust the gray head of Jerry Kerrigan. Though a pair of motor goggles, worn to protect his keen gray eyes from the flying sand, gave his face a grotesque look, it could not completely hide the jovial smile the veteran engineer ever had for the girl of Silver Thistle. The train stopped but long enough to take water. Then the great, black monster, trembling with the power of its mighty strength, leaned to its load, and moved forward, belching a cloud of smoke from its stack. “Oh, say, Neva--” Jerry called back, “I almost forgot: The superintendent’s ‘Special’ is just behind us! And, say--his girl will be with him! Look for her!” The train was gone, with a roar, leaving a smell of burned oil in its wake. Singing again, even more joyfully, Nevada stood by the window, watching for the “Special.” There came another rumbling roar from down the track, followed by another musical call of a locomotive’s whistle, and a minute later the “Special” had come to a halt at the water tank. There were only two cars--a pitiful load it seemed for that great, high-wheeled engine. The rear car alone attracted the attention of the desert girl. Her eager eyes took in every detail, and a happy smile brightened her face when she saw the name, painted in gold letters on the side. She repeated the name aloud: “Debue! Debue!” While she looked, a girl came out on the rear platform, to stand for a while inside the brass railing. Behind her followed a portly, white-haired man--a man whose features and bearing portrayed power and purpose and leadership. Nevada’s heart fluttered exultantly, for the girl was the one who had smiled down at her through the wide window of the coach--and the man who stood near her was Superintendent Foster. To Nevada’s ear came the joyful exclamation of the girl: “Oh, how lovely they are! I must have some of them. Please, father, can’t I have just a minute to pick some of them?” Then she turned her big, appealing eyes to her father, and the superintendent with a smile, nodded his assent. “Go ahead, my dear! But be careful--and stay only a minute.” Wondering what it was the girl had admired and wanted, Nevada watched while a porter opened the railing gate and placed a footstool under the lower step. The girl tripped down lightly and ran out across the right-of-way. Nevada followed her with keenly interested gaze. When the girl uttered another exclamation of delight, Nevada knew what it was that had attracted her. She was plucking the tall thistles--the long-stemmed, silver-plumed thistles that had given the isolated station its name. [Illustration: She was plucking the tall thistles.] Nevada, too, had admired the silver thistles--admired them for their hardihood, their happy way of nodding their plumed heads in pleasant salutation when nearly all other growing things were dried up, blistered and burned by the desert heat....