"Abaris' frog-like features parted in a grin. His throat rattled mirthfully. I stared at him, awed. "'Hoh, hoh, hoooah!' My mind throbbed under the force of his booming mental laugh. 'Why, lowly worm!' he shot, his tubes pointing straight at me, 'If I but minded to I could destroy your entire world with one little globule of radium!' "'What do you mean?' I asked with a sudden desire to learn all I could concerning these strangers and their awe-inspiring powers. "'Just this!' Abaris said, evenly and with sarcasm, 'We of Jupiter are so far your superiors that you are but worms in comparison. When your people were still clinging by their tails we of Jupiter had already mastered mathematics. During the years that followed and developed you to your present state, we of Jupiter mastered many sciences--one of which brings us to your world now. That is radium. We have mastered radium in all its forms and we are therefore masters of the Universe and all life in it.' "'Well,' I said, 'why didn't you destroy us here on earth then if you are so powerful? How did you get here on this earth if your planet is Jupiter?' "'We, Man of the Earth,' he said, amused, as though enjoying the mental conversation immensely and taking great pride in the vast knowledge of his people, 'we do not take life without cause, even though that life is no more to us than your reptiles are to you!' "'Then why did you kill my friend?' I queried, earnestly. 'Why have you held these two white people with you?' "'Your friend is unhurt physically, but mentally he now belongs to Jupiter! His intentions were doubtful when he leaped up here beside Eloli, whom your feeble mind refers to as Allie Lane! I should have killed him instantly!' "I felt unable to think of anything for a moment, and I stared fascinated at the features that confronted me. I noticed that the colors in the chamber were changing again and that the lackadaisical visage of Abaris was growing more pronounced under the varying hues. His saucer-like eye-lids continued their resounding clap-clap-clap like the sound of shutters closing on a camera. "'I don't believe you, Abaris!' my voice suddenly raised. 'You killed him because you knew that he was Allie Lane's man by all the laws of humanity on this world!' "'What care we Jovians for the laws of your humanity!' Abaris' thought wave struck me sharply. 'I could have killed you both instantly! You were trespassing on forbidden ground and I therefore had the right to remove you from it!' "'How did you know we were here?' I asked. "'Our sentinels on the surface informed us of your coming long before you reached here. We had no intention of harming you unless you entered the crater!' "'Then that's why you hung up these skeletons out there--to scare us away, eh?' I inquired. 'Did you think a few grinning skulls would make us run?'