Through what connivance Price was the second time enabled to escape, probably never will be known. At that time it was as much a mystery as was the disappearance of Lieutenant Avery and his bride, and there was a strong inclination in the army toward the belief that both were engineered by the same hand. Nothing could be proved, however, and it remained a mystery for some time. CHAPTER XXXIII. WONDERFUL MIRROR OF THE PLAIN. “Buffler, what d’ye make out o’ thet mirrij?” Old Nomad had aroused the scout very early to look at the sky, which reflected the plain for miles. The pards had camped the previous evening in a basin in the broken clay of the Bad Lands where the rains had formed a miniature lake, around which grass had started up luxuriantly. The place resembled an immense “buffalo wallow” and had all the appurtenances in the way of “buffalo flies” which at first threatened to drive the thin-haired horses into a stampede, when the party first arrived late in the afternoon. But a flock of starlings came soon after and, alighting on the horses, soon put the flies to rout. Cayuse had stumbled upon the place in the afternoon and it was decided to remain where there was good grazing and plenty of water, although the latter was not an attractive quality. Hidden from the surrounding country, with the breeze sweeping across the pool, after the sun went down the pards found it to be a delightful camping ground. They slept soundly, and although two-hour watches placed each, with the exception of Tootsie, on guard during the night, not the slightest cause for alarm was discovered. It was old Nomad’s morning watch and he had finally awakened Buffalo Bill to study a beautifully clear mirage, which depicted a scene that puzzled the trapper. The young reader may not know that the phenomenon referred to is extremely common in some localities, and due to atmospheric conditions. It is usually caused by a diminution of the density of the air near the surface of the earth, often produced by the radiation of heat, the denser stratum being thus above instead of below the rarer, which latter is the usual case. Now, rays of light from a distant object, situated in the denser medium--that is, a little above the earth’s level--coming in a direction nearly parallel to the earth’s surface, meet the rarer medium at a very obtuse angle, and instead of passing into it, they are reflected back to the dense medium, thus acting as a mirror.