A key rattled in the lock and the door swung open to admit the handsomest man they had ever set eyes on. He was taller than Frank by several inches, standing no less than six feet five in his thin-soled sandals, and he carried himself with the air for an emperor. His marble-white body was uncovered with the exception of a loin cloth of silver hue, and lithe muscles rippled beneath his smooth skin as he advanced to meet the prisoners. His head, surmounted by curly hair of ebon darkness, was large, and his forehead high. The features were classic and perfectly regular. The corners of his mouth drew upward in a benign smile. "Greetings," he said, in perfect English and in a soft voice, "to the domain of Theros. You need fear no harm from our people and will be returned to the upper world when the time comes. We hope to make your stay with us enjoyable and instructive, and that you will carry back kind memories of us. The morning meal awaits you now." * * * * * So taken aback were the two young Americans that they stared foolishly agape for a space. Then a tinkling laugh from the tall stranger set them once more at ease. "You will pardon us, I hope," apologized Frank, "but this is all so unexpected and so unbelievable that your words struck me speechless. And I know that my friend was similarly affected--We place ourselves in your hands." The handsome giant nodded understanding. "No offense was taken," he murmured, "since none was intended. And your feelings are not to be wondered at. You may call me Orrin." He turned toward the open door and signified that they were to follow him. They fell in at his side with alacrity, both suddenly realizing that they were very hungry. They followed in silent wonderment as Orrin led the way to a broad balcony that overlooked a great underground city--a city lighted by the soft glow from some vast lighting system incorporated in its vaulted ceiling high overhead. The balcony was many levels above the streets, which were alive with active beings of similar appearance to Orrin, these speeding hither and yon by means of the many lanes of traveling ways of which the streets were composed. The buildings--endless rows of them lining the orderly streets--were octagonal in shape and rose to the height of about twenty stories, as nearly as could be judged by earthly standards. There were no windows, but at about every fifth floor there was an outer silver-railed balcony similar to the one on which they walked. The air was filled with bowl-shaped flying ships that sped over the roof tops in endless procession and without visible means of support or propulsion. Yet the general effect of the busy scene was one of precise orderliness, unmarred by confusion or distracting noises. * * * * *