not probable,” was the answer. “Then what do you make of it?” Margaret asked. “I don’t,” was the smilingly given reply. “But I do know that we will all starve and that Sing Long will be on the rampage if we don’t go out and eat the fine breakfast he has prepared for us.” “Whizzle! I have been so interested and excited that I had actually forgotten that I am almost starved,” Betsy declared as they entered the big sunny kitchen, at one end of which was a table that could seat twelve without crowding, for, on the desert, one never knew when a passing cowboy, or a group of them, might stop at meal time. When the first pangs of hunger had been satisfied, Virginia said: “Now brother, tell us your theory.” “I’d like to hear Betsy’s first.” Malcolm was much amused by the small, bright-eyed girl who took such an unusual interest (for one feminine) in the solving of mysteries. They all turned to listen and so Betsy began. “Well, of course I know very little about the ways of the desert, but I should think that Virginia’s suggestion, a little while ago, might be the right one. But since you doubt it, Malcolm, I’m beginning to think that the something the writer didn’t know what to do with, might not be the stolen yearlings after all.” The lad nodded. Then glancing at Margaret, he asked, “Who else has a theory?” Flushing prettily as she always did when her guardian addressed her, the quiet Megsy replied, “I don’t believe that I have one, but I just know that you have, Malcolm. Won’t you tell it to us?” “I may be wrong,” the lad began, “but, from the wording of the memorandum, I believe a boy has written it, and surely a tenderfoot, else he would not have tried to cross the desert in a prairie schooner, if that’s what he has. Maybe he’s here for his health. Many a lad finds his lungs in danger after years of hard study, and they come out here to rough it and get strong again. Anyway, that’s my guess. I don’t believe that the writer of this note has ever even heard of our lost yearlings.” “Hark!” Virginia cried, springing up and running to the door. “What’s all the commotion outside?” There was indeed a most unusual commotion not far away, but, from the kitchen window nothing could be seen but the sandy door-yard, the chicken corral, the outhouses and farther down the slope and near the