But, even as she spoke, a change came. The light faded away as when a thunder-cloud crosses the sun, and in a second or two they were in complete darkness. Burke groped about for the switch that turned on the lights.
"What’s happened?" gasped Rhoda. "Are we falling?" And she reached out in the dark and clutched Bennie’s hand. "Has anything gone wrong?"
"No," he reassured her; "we’ve merely entered the moon’s shadow—that’s all. Give her some more lift, Burke. We mustn’t take any chance of dropping back. Don’t turn on the light. We’re all right, and I want to have a look at the moon."
Again they felt the upward push of the floor and knew that they were rising. Bennie, flat on his face, gazed into the blackness beneath them. Nothing was visible, however, and he pres-called for the lights.
"Now for our bearings," he remarked, climbing to his perch under the telescope. Looking up through the window above, he saw the greenish globe of the asteroid nearly overhead. "Hello," he commented, as he focused his telescope; "it’s been coming on fast while we were camping on the moon! All the surface markings are perfectly visible through the glass. And every minute they’re growing more distinct."
"What does it look like?" asked Rhoda.
"Looks more like an English walnut than anything else," he mumbled. "There’s a funny big spot—perfectly smooth—right in the center of the disk, and hundreds of queer ridges and furrows running from it in every direction."
Rhoda bade farewell to the moon and, throwing herself on her back on a wicker lounge, gazed up through the window overhead, watching the asteroid grow steadily larger. In something over an hour it had nearly doubled in size—a venomous-looking creature glowing with a sulphurous luminosity that filled her with a certain vague apprehension. The crescent earth was now close to the fast-subsiding horizon of the moon, and hung a silvery target for the projectile, which, if not interrupted in its flight, would inevitably annihilate it. Her pulses stirred at the realization that they could avert - if all went well - this catastrophe. Theirs was surely the greatest "still hunt" ever undertaken—if they only could bag their celestial game—bring down their quarry, like a quail!
"It’s time to get ready," announced Bennie, from the observation-stage. "Burke, stand by to turn over!"
"Aye! Aye!" replied Burke, his fingers on the lever.
"Start the dynamo, Atterbury!" ordered the master of the Ring.
Outside, the glare of the helium ray once more poured down through the center of the machine.
"Hard alee!" called Bennie.
Burke threw over the control-lever, and the great car slowly inverted itself. Then the engines stopped, and silence reigned again. Bennie joined Rhoda at the deadlight. Medusa was now about the size of the full moon as seen from the earth, while the real moon had shrunk away until it was apparently about the size of the earth itself. Through the windows they could see sun, moon, and earth, all at once, surrounded by millions of constellated stars against a background of darkness. Beneath them hung Medusa—the sidereal battleship which they hoped to torpedo—not more than twelve hundred miles away!
"At what range are you going to fire?" asked Rhoda. "I suppose the longer you wait and the nearer we get, the greater will be the effect of the ray?"
"On the contrary," he replied. "The distance from which the ray is discharged is immaterial, so long as the rays are concentrated upon the object to be destroyed."
"How far are we away from Medusa now?" she asked.
"Judging by the observed diameter of the asteroid, I should say about a thousand miles. Of course, the nearer we are the better target Medusa will make, but we shall have to attack at a sufficiently great distance to avoid danger from the radioactive discharge from its surface which the ray will produce."
"Particularly as Medusa is a ’uranium planet,' she agreed. "Of course, I don’t suppose you quite know what will happen when the ray strikes?"
"No," he answered; "everything depends on the nature of the material. If it is a pure ore of uranium, there will be no explosion but only a radioactive discharge from the surface, which will drive the asteroid out of its present path. If there are other materials present, things will fly. Medusa is about one hundred and fifty miles in diameter. It is scarcely conceivable that our ray could actually break it up. But I’m not going to take any chances. Medusa may be within range now. I think we had better try her at this distance."
Through their glasses, they could easily see that on one side
the surface of the asteroid was pitted with holes and craters similar to those upon the moon, while the other, which had been subjected to the fierce erosion of the dense gases of the comet, was worn almost smooth and plowed into furrows. The Ring was now moving on a course parallel to that of Medusa, which floated apparently motionless in space at a distance which Bennie estimated to be less than five hundred miles. Both, drawn by the combined attraction of the sun and earth, were in reality rushing on toward the latter. The three men were busy with their preparations for the projection of the great ray, and Rhoda drew herself over to the side deadlight, through which streamed the pale-yellow beams from the runaway planet* Now that they were running alongside, but one-half of the illuminated hemisphere was visible, and Medusa appeared like the moon at the half-phase, but fifty times as big.
Monstrous and sinister it looked to her, and she shuddered involuntarily as she thought of its distant target, peopled with millions of helpless human beings, doomed to be wiped out of existence in a blinding flash of fire. Could they do aught to prevent it—four insects in a flying pellet of metal, aspiring to stop a runaway world? Had not perhaps the thing been put in motion by some Supreme Intelligence which controlled the universe, and might not the destruction of the world be a part of the Great Plan, a cog in the great wheel of destiny? If so, what could they hope to do to alter the plan? And then she thought of the taming of the thunderbolt by the lightning-rod, and drew a long breath and clenched her hands. Man had, from the beginning, devised ways and means of averting impending disasters due to the forces of nature. The present case differed in no respect from the others except in magnitude. The evolution of defense against nature had been steady and progressive, from the stone age, when prehistoric man sought shelter in caves from the pelting hailstones, to the present one in which they were about to whip out of its course a planet that was running wild through the solar system.
There in front of her, just outside the deadlight through which she was gazing, and silhouetted against the shining disk of the asteroid, was that terrible weapon, the generator of the disintegrating ray. In a few minutes, it would be hurling its mysterious beam across the void of space. She would be present, and would see what happened* Already, the Ring was reverberating with the noise of the machinery for generating the electric current that fed the coils of the inductor. Both dynamos were running at full-speed, and the scream of the radio-turbines filled the air. Through the din, she heard Bennie’s voice—"Clear for action!’’ Burke brushed past her and took his post at the switchboard beside the deadlight, from which the motors that swung the inductor on its trunnions were operated. She clutched the rail in front of her, with her eyes fixed on the black cylinder of metal that hung, pivoted on its skeleton supporting-frame, not five yards from her face. Womanlike, she wanted to put her fingers in her ears, but
she was afraid to let go of the rail.
"All ready!" called Bennie. "Get your aim, Burke!"