He stood at the center of an enormous horseshoe formed on the southwest by the range curving farther toward the south, and on his left hand, by the same range sweeping in a quarter-circle toward the southeast. The mouth of this granite half-circle was opened to the south, at least a quarter-mile in width; but on his left, a jutting spur almost at right angles to the main range, and some hundreds of yards closer to his position, shot across the space within the horseshoe bend, in such fashion that an observer, standing on the plain, would have half his view of the inner concave expanse shut off, except that part of the high north wall that towered above the spur. Nor was this all. Behind the perpendicular arm, or spur, that ran out into the sea of mesquit, rose a low hill that was itself in the nature of an inner spur although, since it failed to reach the mountain, it might be regarded as a long flat island, surrounded by the calm green tide. This innermost arm, or island, was so near the mountain, that the entrance to it opened into a curved inner world of green, was narrow and strongly protected. The cove thus formed presented a level floor of ten or twelve acres, and it was directly down into this cove that Willock gazed. It looked so peaceful and secure, and its openness to the sunshine was so alluring, that Willock resolved to descend the steep wall. To do so at that point was impractical, but the ridge was unequal and not far to the right, sank to a low divide, while to the left, a deep gully thickly set with cedars, elms, scrub-oaks and thorn trees invited him with its steep but not difficult channel, to the ground. "Here's a choice," observed Willock, as he turned toward the divide; "guess I'll go by the front, and save the back stairs for an emergency." The gully was his back stairs. He was beginning to feel himself rich in architectural possibilities. When he reached the plain he was outside of a line of hummocks that effectually hid the cove from sight, more effectually because of a dense grove of pecans that stood on either side of the grass-grown dunes. Instead of crossing the barrier, he started due south for the outer prairie, and when at last he stood midway between the wide jaws of the mountain horseshoe, he turned and looked intently toward the cove.