The girl was quite unconscious of the fact that a young man was tramping up the desert behind her. He, however, had spied the white gown long before Rhoda had sunk to the rock and had laid his course directly for her. He was a tall fellow, standing well over six feet and he swung through the heavy sand with an easy stride that covered distance with astonishing rapidity. As he drew near enough to perceive Rhoda's yellow head bent above her injured foot, he quickened his pace, swung round the yucca thicket and pulled off his soft felt hat. "Good-morning!" he said. "What's the matter?" Rhoda started, hastily covered her foot, and looked up at the tall khaki-clad figure. She never had seen the young man before, but the desert is not formal. "A thing like a little crayfish bit my foot," she answered; "and you don't know how it hurts!" "Ah, but I do!" exclaimed the young man. "A scorpion sting! Let me see it!" Rhoda flushed. "Oh, never mind that!" she said. "But if you will go to the Newman ranch-house for me and ask them to send the buckboard I'll be very grateful. I--I feel dizzy, you know." "Gee whiz!" exclaimed the young man. "There's no time for me to run about the desert if you have a scorpion sting in your foot!" "Is a scorpion sting dangerous?" asked Rhoda. Then she added, languidly, "Not that I mind if it is!" The young man gave her a curious glance. Then he pulled a small case from his pocket, knelt in the sand and lifted Rhoda's foot in one slender, strong, brown hand. The instep already was badly swollen. "Hold tight a minute!" said the young man. And before Rhoda could protest he had punctured the red center of the swelling with a little scalpel, had held the cut open and had filled it with a white powder that bit. Then he pulled a clean handkerchief from his pocket and tore it in two. With one half he bound the ankle above the cut tightly. With the other he bandaged the cut itself. "Are you a doctor?" asked Rhoda faintly. "Far from it," replied the young man with a chuckle, tightening the upper bandage until Rhoda's foot was numb. "But I always carry this little outfit with me; rattlers and scorpions are so thick over on the ditch. Somebody's apt to be hurt anytime. I'm Charley Cartwell, Jack Newman's engineer." "Oh!" said Rhoda understandingly. "I'm so dizzy I can't see you very well. This is very good of you. Perhaps now you'd go on and get the buckboard. Tell them it's for Rhoda, Rhoda Tuttle. I just went out for a walk and then--" Her voice trailed into nothingness and she could only steady her swaying body with both hands against the rock. "Huh!" grunted young Cartwell. "I go on to the house and leave you here in the boiling sun!" "Would you mind hurrying?" asked Rhoda. "Not at all," returned Cartwell. He plucked the stocking and slipper from the yucca and dropped them into his pocket. Then he stooped and lifted Rhoda across his broad chest. This roused her.