Stevens had poised the "Forlorn Hope" edgewise in mid-air, so that the gleaming, heavily armored parabolic reflectors of his projectors, mounted upon the leading edge of the fortress, covered the scene below. As the charred corpse of the savage chieftain dropped to the ground, it seemed to the six-limbed creatures that the demons of the falls had indeed been annoyed beyond endurance by their intrusion; for, as if in response to the flash of fire from the power plug, that structure so peculiarly and so stolidly hanging in the air came plunging down toward them. From it there reached down twin fans of death and destruction: one flaming and almost invisibly incandescent violet which tore at the eyes and excruciatingly disintegrated brain and nervous tissues; the other dully glowing an equally invisible red, at the touch of which body temperature soared to lethal heights and foliage burst cracklingly into spontaneous flame. In their massed hundreds, the savages dropped where they stood, life rived away by the torturing ultra-violet, burned away by the blast of pure heat, or consumed by the conflagrations that raged instantly wherever that wide-sweeping fan encountered combustible material. In the face of power supernatural they lost all thought of attack or of conquest, and sought only and madly to escape. Weapons were thrown away, the catapults were abandoned, and, every man for himself, the mob fled in wildest disorder, each striving to put as much distance as possible between himself and that place of dread mystery, the waterfall. "Well, I guess that'll hold 'em for a while," Stevens dropped their craft back into its original quarters in the canyon. "Whether they ever believed before that this falls was inhabited by devils or not, they think so now. I'll bet that it will be six hundred Jovian years before any of them ever come within a hundred kilometers of it again. I'm glad of it, too, because they'll let our power plant alone now. Well, let's get going--we've got to make things hum for a while!" "Why all the rush? You just said that we have scared them away for good." "The savages, yes, but not those others. We've just turned loose enough radiation to affect detectors all over the system, and it's up to us to get this beam projector set up, get away from here, and get our power shut off before they can trace us. Snap it up, ace!" The transmitter unit was installed at the converters, the cable was torn out, and, having broken the last material link between it and Ganymede, Stevens hurled the "Forlorn Hope" out into space, using the highest acceleration Nadia could endure. Hour after hour the massive wedge of steel bored outward, away from Jupiter; hour after hour Stevens' anxious eyes scanned his instruments; hour after hour hope mounted and relief took the place of anxiety as the screens remained blank throughout every inquiring thrust into the empty ether. But they knew they would have to keep sharp vigilance.