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 battle-ship 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?"