A level line above marked the rim of the plateau. Sand began to show in the little lava pits. On and upward toiled the cavalcade, still very slowly advancing. At last Yaqui reached the rim. He stood with his hand on Blanco Diablo; and both were silhouetted against the sky. That was the outlook for a Yaqui. And his great horse, dazzlingly white in the sunlight, with head wildly and proudly erect, mane and tail flying in the wind, made a magnificent picture. The others toiled on and upward, and at last Gale led Blanco Sol over the rim. Then all looked down the red slope. But shadows were gathering there and no moving line could be seen. Yaqui mounted and wheeled Diablo away. The others followed. Gale saw that the plateau was no more than a vast field of low, ragged circles, levels, mounds, cones, and whirls of lava. The lava was of a darker red than that down upon the slope, and it was harder than flint. In places fine sand and cinders covered the uneven floor. Strange varieties of cactus vied with the omnipresent choya. Yaqui, however, found ground that his horse covered at a swift walk. But there was only an hour, perhaps, of this comparatively easy going. Then the Yaqui led them into a zone of craters. The top of the earth seemed to have been blown out in holes from a few rods in width to large craters, some shallow, others deep, and all red as fire. Yaqui circled close to abysses which yawned sheer from a level surface, and he appeared always to be turning upon his course to avoid them. The plateau had now a considerable dip to the west. Gale marked the slow heave and ripple of the ocean of lava to the south, where high, rounded peaks marked the center of this volcanic region. The uneven nature of the slope westward prevented any extended view, until suddenly the fugitives emerged from a rugged break to come upon a sublime and awe-inspiring spectacle. They were upon a high point of the western slope of the plateau. It was a slope, but so many leagues long in its descent that only from a height could any slant have been perceptible. Yaqui and his white horse stood upon the brink of a crater miles in circumference, a thousand feet deep, with its red walls patched in frost-colored spots by the silvery choya. The giant tracery of lava streams waved down the slope to disappear in undulating sand dunes. And these bordered a seemingly endless arm of blue sea. This was the Gulf of California. Beyond the Gulf rose dim, bold mountains, and above them hung the setting sun, dusky red, flooding all that barren empire with a sinister light.