He had finished and was reaching for his hat when footsteps were heard on the hard-beaten dooryard. They were slow, lagging, unfamiliar to the listeners, who looked at each other inquiringly. Then the Indian woman threw open the door, and Susie, like the ghost of herself, staggered from the darkness outside into the light. No ordinary fatigue could make her look as she looked now. Every step showed complete and utter exhaustion. Her dishevelled hair was hanging in strands over her face, her eyes were dark-circled, she was streaked with dust and grime, and her thin shoulders drooped wearily. "Where you been, Susie?" her mother asked sharply. "Teacher said," she made a pitiful attempt to laugh, to speak lightly--"Teacher said ridin' horseback would keep you from gettin' fat. I--I've been reducin' my hips." "Don't you do dis no more!" "Don't worry--I shan't!" And as if her mother's reproach was the last straw, Susie covered her face with the crook of her elbow and cried hysterically. Ralston was convinced that the day had held something out of the ordinary for Susie. He knew that it would take an extraordinary ride so completely to exhaust a girl who was all but born in the saddle. But it was evident from her reply that she did not mean to tell where she had been or what she had been doing. Although Ralston soon retired, he was awake long after his numerous room-mates were snoring in their bunks. There was much to be done on the morrow, yet he could not sleep. He was not able to rid himself of the thought that there was something peculiar in the absence of Smith just at this time, nor could he entirely abandon the belief that McArthur would yet come straggling in, with an explanation of the whole affair. He could not think of any that would be satisfactory, but an underlying faith in the little scientist's honesty persisted. Toward morning he slept, and day was breaking when a step on the door-sill of the bunk-house awakened him. He raised himself slightly on his elbow and stared at McArthur, looming large in the gray dawn, with a skull carried carefully in both hands. "Ah, I'm glad to find you awake!" He tiptoed across the floor. His clothing was wrinkled with the damp, night air, and his face looked haggard in the cold light, but the fire of enthusiasm burned undimmed behind his spectacles. "Congratulate me!" "I do--what for?" "My dear sir, if I can prove to the satisfaction of scientific sceptics that this cranium is not pathological, I shall have bounded in a single day--night--bounded from comparative obscurity to the pinnacle of fame! Undoubtedly--beyond question--a race of giants existed in North America----" "Pardon me," Ralston interrupted his husky eloquence; "but where have you been all night?"