Sine was awakened by the talking of Kass and Lents as they sat at their breakfast in their unimaginably luxurious apartment. They were near the top of one of the fairylike towers they had glimpsed, and through the crystalline roof they could see the blackness of star-studded space. Far above was the glint of slanting sunlight on the outer covering of the sphere. This was the fourth morning on The Bubble, and the Earthmen were beginning to become vaguely restless. Their hosts had entertained them royally, but-- "I didn't see anything funny about the way they shoved that labor Mug out of the airlock," Lents was saying. "The poor devil! Stole a little of the juice they call ambrosia. The way that elegant over-civilized crowd laughed!" "They lined up and watched the body floating alongside," Kass added somberly. "And that Mug was as human as you or I." Their words recalled the scene vividly to Sine's mind. The broad, green field between two crescent lakes. The beetling-browed wretch, with eyes full of fear that darted from side to side, led to the center of the field by two splendidly armed warriors, there to be left alone in an agony of uncertainty. He saw again the half-hundred clean-limbed athletes, sons of rich Jovian families. They were lined upon each side of the field. At the signal they dashed in. The frightened labor Mug tried to escape. As one team closed in he doubled, ran directly toward the others, saw his mistake too late. There was a brief savage scrimmage, and the unfortunate victim was stretched unconscious on the sward, while the victors and the vanquished in this curious game joined arms and made for the baths where exquisite nymphs peered coquettishly from behind delicately proportioned columns. Sine reaped uncomprehending and resentful stares when he declined to join them. "Too rich for my blood," Sine told his companions at breakfast as they discussed their experiences. "Hope they take us to Rubio soon. We've done our job, and as for me, I'm not cut out for high Society." After they had completed their breakfast a girl came hesitatingly into their chamber. Sine stared at her curiously. She had none of the enameled beauty of the women he had seen until then, but in her young face was a subdued comeliness that was attractive after the assertive pulchritude that was universal among the young women of the First Race. Unlike the shrewd display of their chiseled perfection, this girl's slender, rounded body was wrapped in a thin, gray garment that concealed as it draped. It was caught by a cord around her waist. Her feet, smaller and more fragile than the sturdy Jovian standard, were encased in neutral buskins. She stood submissively, waiting for them to speak. "What does that girl want?" Kass murmured aside. "My stars, she can't be a labor Mug!" "Come here, girl!" Lents rumbled kindly. "What can we do for you?" The girl came forward hesitatingly. Her voice was soft, lacking the brassy assurance of other Jovian women;