Curt turned at the sound of footsteps behind him. That would be Olana. She, too, came here each week. She stopped beside him, raised her helmeted face to Sun and stars with infinite longing. For a moment neither of them spoke. Then Olana clicked on her helmet radio. "Each time, Curt ... each time I come here I imagine the Sun has grown dimmer. Is it really only my imagination?" "Yes. It becomes dimmer, but not perceptibly. Solar radiation is electronic, and the theory is that our Sun has merely exhausted an outer sheath of electrons. Lord knows what internal condition caused it! If it's a solid body, it may be due to certain peculiarities of the strata. The sun spots of hundreds of years ago must have been the beginning of the end." She nodded. "How is the work coming?" "The Traction Rays? Slowly, Olana--too slowly." Curt shook his head in weariness. "We're in the process of testing, but they are still not strong enough. It means months more of work, and we shall need hundreds! You know, if we fail on the first attempt we shall not have another chance." "I--I still don't quite understand it," Olana was puzzled. "I know it has something to do with the orbit of Vulcan. But how can it save us?" "It may not. It's a forlorn chance. You know of course that Vulcan's a very small planet, scarcely larger than Earth's moon. And it pursues an orbit much closer to the Sun than Mercury. If we can drive it out of its orbit with the Traction Rays, it may fall into the Sun!" "But suppose," Olana pointed out, "it only takes up a closer orbit?" "Exactly why we're taking no chances. We must be sure our rays are strong enough to _propel_ it into the Sun." "And what then?" Curt shrugged. "After that it's anybody's guess. Professor Marston believes that such a collision will set up a combustion sufficient to release internal electronic action from the Sun's depths. And, once that is started, the Sun will blaze again." "I see," Olana exclaimed. "Something like stirring up dying embers!" "Yes." There was no eagerness in Curt's voice. "No doubt there are forces within the Sun sufficient to last for millennia, if they could only be released. But they must be deep within. I'm afraid nothing we do with Vulcan will be enough." "Why, you're just a pessimist!" Curt smiled wanly. "No, just realistic. And very tired! It's been a trying week. Come, we'd better be getting back." "Wait." Olana stopped him. She was gazing at the blackness beyond the horizon's rim. "Curt, look." "Meteor?" He followed her gaze. "No! I never saw a meteor like _that_!" They saw a patch of light against the reddish sunglow. It wasn't extended light, it seemed to move as a bulk and with such speed as no meteor had ever attained. For half a minute they watched it become smaller--then it disappeared. Curt shook his head in puzzlement. [Illustration: _They saw a patch of light against the reddish sunglow._]