It was only a short mile from the camp on the inward slopes of the eastern foot-hills to the mouth of the outlet gorge, across which Brouillard could already see, in mental prevision, the great gray wall of the projected Niquoia dam--his future work--curving majestically from the broken shoulder of Chigringo to the opposing steeps of Jack's Mountain. The half-grown moon, tilting now toward the sky-line of the western barrier, was leaving the canyon portal in deepest gloom. As Brouillard swung along he kept a watchful eye upon the gorge shadows, half expecting a return of the mysterious apparition. But when he finally reached the canyon portal and began to seek for the trail which roughly paralleled the left bank of the stream the mystery was still unexplained. From its upper portal in the valley's throat to the point where the river debouches among the low sand-hills of the Buckskin Desert the canyon of the Niquoia measures little more than a mile as the bird flies, though its crookings through the barrier mountains fairly double the distance. Beginning as a broken ravine at the valley outlet, the gorge narrows in its lower third to a cliff-walled raceway for the torrent, and the trail, leaving the bank of the stream, climbs the forested slope of a boundary spur to descend abruptly to the water's edge again at the desert gateway, where the Niquoia, leaping joyously from the last of its many hamperings, becomes a placid river of the plain. Picking his way judiciously because the trail was new to him, Brouillard came in due time to the descending path among the spruces and scrub-pines leading to the western outlook upon the desert swales and sand-hills. At the canyon portal, where the forest thinned away and left him standing at the head of the final descending plunge in the trail, he found himself looking down upon the explanation of the curious apparition. None the less, what he saw was in itself rather inexplicable. In the first desert looping of the river a camp-fire of piñon knots was blazing cheerfully, and beside it, with a picnic hamper for a table, sat a supper party of three--two men and a woman--in enveloping dust-coats, and a third man in chauffeur leather serving the sitters. Back of the group, and with its detachable search-light missing, stood a huge touring-car to account for the picnic hamper, the dust-coats, the man in leather, and, doubtless, for the apparitional eye which had appeared and disappeared at the mouth of the upper gorge. Also it accounted, in a purely physical sense, for the presence of the picnickers, though the whim which had led them to cross the desolate Buckskin Desert for the dubious pleasure of making an all-night bivouac on its eastern edge was not so readily apparent.