For Thornton had never doubted that the Ring would start. He had known Hooker, boy and man, for nearly thirty years, knew that he was a practical as well as a brilliant scientist, and, when Pax had threatened to knock the earth topsyturvy, had himself been the one to rout the professor out of his scholastic seclusion on the Appian Way in Cambridge, and stimulate him to those investigations which shortly resulted in the discovery of the valley of the Ring in Ungava and the navigation of the air-craft back to the United States.

Thornton did not question the ability of Hooker and his comrades to navigate space in the great machine, or the power of the lavender ray to destroy Medusa or any other heavenly body. What he feared was the unknown factor of chance, always arising when an experiment is hazarded under new conditions. What did they know of space? Would their liquid-air tanks accomplish their purpose? What would be the effect of the complex and opposing forces of attraction to which, once outside the sphere of the earth's gravitation, this new man-made meteor would be exposed? Could the Ring be "turned" so as properly to alight? Would it turn? Would the human organs function under these extraordinary artificial conditions? Would, in fact, the brain work properly or logically when no natural premises were left from which to reason? Well, they would see! But the Ring would start! Oh, yes, it would start—and its departure would be caught on the film of the automatic moving-picture astronomical camera attached to the big telescope—provided, of course, that he succeeded in following its meteoric flight.

The observatory stood on the top of a small hill, and, from his window, Thornton could see across a sea of tumultuous housetops, colorless in the moonlight, to a dark strip where lay the aerodrome.

He raised his eyes and gazed up through the heavens, that looked almost like a field of pale-blue corn-flowers sprinkled with a myriad of daisies, into the deeper blue of the infinity behind and beyond the Milky Way, just as he had looked through his big telescope now for nearly thirty years. That vast, blue-black arch had always looked the same—save for the slight changes in the celestial bodies themselves which were his life-study. Blue, deep blue—flash! Suddenly the heavens were no longer blue but dazzling white. The silence of night was shattered by a roar from the sky above the aerodrome. The Ring! It was off!

Half blinded by the glare, he rushed to the equatorial-room. Already the intense brilliancy had died away, but through the yawning gap in the roof he caught a glimpse of a fast-fading streak of yellow light. Toward this streak, he turned the telescope—but it was no longer there! Upward again—and then, at last, he caught it in the finder—a glowing dot—and brought the cross-wire upon it—only to lose it, so rapid was its flight. Once more, and a third time, he caught it on the cross-thread, but it passed out of the field of the larger instrument before he could shift the position. A fear that he would never succeed in bringing the giant lenses to bear upon it seized him. He knew that if he could not pick it up within the first few minutes, it would be hopeless to find it.

Then, unexpectedly, there it was—slowly descending into the field of the telescope, its yellow beam pointing directly upward. For a moment, he almost forgot that the astronomical telescope inverts the object. Once more he fixed his eye at the finder. He could see distinctly the under surface of the Ring, illuminated by the light of the glowing gas which streamed beneath it, while the blinding glow of the helium jet, seen nearly end-on, looked like a great ball of fire in its center. It reminded him forcibly of the planet Saturn. Was it possible that his old friend Bennie Hooker, with two companions, was inside of that minute, flaming pellet?

Momentarily it grew smaller. The minutes passed; the hour came and went, and still Thornton stuck at his post. At nine-fifty, all that he could see was a faint wisp of pale-yellow light, like an almost invisible comet. He estimated that it would remain visible for perhaps fifteen minutes more, and then—good-by!

Suddenly, to his utter amazement, it commenced to fade, and in eight or ten seconds more it vanished. He wiped his glasses and anxiously looked again. There was no sign of the Ring whatever. He glanced up at the sky over the telescope, but it bore no trace of cloud. The Ring had been completely swallowed up in the abyss of space!

"Good God," he thought, "something has gone wrong, and they are falling back!"

He did not know that the Ring was at that moment flying out into space with a velocity of over twenty miles a second, and that Hooker had stopped his driving machinery and was depending upon the momentum of his machine to carry him over the remainder of his journey—in other words, that he was coasting out to his encounter with the asteroid Medusa.