The Eastern girl laughingly held up a black broadcloth riding habit with a long tailored coat and a stiff black derby. “This doesn’t look much like a cowgirl costume,” she said gaily. “How I do wish I had a khaki suit like yours.” “So you shall have as soon as we can get to town, but today you may wear my extra one. I always keep two in readiness least a mishap befall one of them. I’ll get it in a twinkling.” Half an hour later the girls were starting on their ride across the desert and toward the Slater Ranch. Margaret, in her cowgirl costume, made a very pretty picture. “How I wish Babs could see me now!” she said as the two girls, after a canter side by side, drew rein to go single file down the steep trail leading across Silver Creek which at that time of the year was dry and pebbly. Virginia glanced anxiously at Comrade for that pony seemed restive and ill content. “Was it because of the strangeness of the rider?” the girl wondered. She was about to suggest that Margaret hold the rein loosely when the level desert was again reached, but at that moment a sudden whirlwind swept toward them and they were engulfed in blinding sand. Margaret, terrorized by this new and unexpected experience, dragged frantically on the rein. Instantly Comrade reared, and then, dropping again to all fours, he galloped madly ahead at a pace so rapid that Virginia, though she urged Star to his top-most speed, could not overtake him. Margaret knew that her only safety lay in clinging to the horse’s neck and this she did, dropping the rein which flapping in Comrade’s face greatly increased his fright. Although Virginia’s pony strained every muscle, he could not overtake the fright-maddened Comrade. Now and then pausing to snort and rear, again plunging blindly ahead, the red-brown pony suddenly veered and made straight for the mountains. There was a new terror in the heart of Virginia and she greatly feared for the safety of her friend, for the mountain trail was rough and the Eastern girl would surely be thrown against the jagged rocks. Then, to add to Virginia’s dismay, a second whirlwind swept across the desert. She saw it coming and just in time, she wheeled Star about that the sand might not be hurled in their faces. When the air was again clear Comrade and his rider were nowhere to be seen. What had happened, Virginia wondered, sad at heart. Surely they could not have reached the mountain trail as yet. Of course the rider might have been thrown, but the horse, too, had disappeared. Again urging Star to his top speed, Virginia soon neared the spot where she had last seen Comrade. There she drew rein and looked about. “Margaret! Margaret!” she called. “Where are you?” But there was no reply.