Here, however, Kirby thought they must face trouble, for he found that the great walls, of a sparkling, almost glassy smoothness, shot up to a height of at least three hundred feet, and that no path of any sort was visible.
"We're here," he said, "but how can we get up?"
But understanding began to dawn as Naida laughed, and produced from the pouch at the side of her gauzy dress four pliable discs of a substance which resembled rubber.
"You are very strong, are you not?" she asked.
"Then you will have no trouble in following us up the cliff. Our Serpent God, Quetzalcoatl, taught us how to climb long ago."
With that she handed Kirby the set of vacuum discs, and producing another for herself, moistened them in a pool of water close at hand. Then, as all of the girls followed her action, she strapped them to her hands and feet, and in a moment they had begun the ascent.
"Why," Kirby said presently, "with these things you could hang by your feet and walk on a smooth ceiling!"
Naida laughed, and they worked their way upward.
When the climb was accomplished and the discs were put away, Kirby found himself standing on the outer edge of a mediaeval paradise, of a magnificent plateau partly fortified by nature, partly by the hand of man.
"Ah!" he cried in deep admiration, then followed Naida.
The building--the castle--in the near distance, resembled a castle of Spain, save that there was greater beauty and subtlety of architecture. Turreted on all four corners, constructed of material which looked like blocks of natural glass, the fairylike structure was crowned by a gigantic tower of something which resembled obsidian. Up and up this tower soared until its gleaming black tip seemed almost to touch the glassy-radiant sky of the cavern.
No people showed themselves, and Kirby saw that the bronze-studded portals set in the front of the castle were closed.
Admiringly, he glanced at the surrounding land laid out in checkerboard patches of gardens and orchards where grew a bewildering variety of unknown fruits and blooms. Butterflies drifted past, and the air was freighted with the scent of flowers. Inside a walled enclosure, Kirby saw a good-sized plot heavily grown with the plant on which he had been subsisting. As they passed this ground, each of the girls, Naida leading, made a strange little bowing, gliding genuflection, and Kirby wondered.