he perpetual treaty had not been broken since, but the energies of the warlike descendants of those first settlers of Ganymede were expended in casting about for new fields to conquer. Through the ages they cast increasingly covetous eyes on those inner planets, Mars, Terra and Venus. Not having the advantage of the Rulden, they knew of these bodies only what could be seen through their own crude optical instruments and what they had learned by word of mouth from certain renegade Europans they were able to bribe.
While their neighbors of the smaller satellite were engaged in peaceful pursuits, tilling the soil and making excellent homes for themselves, the dwellers on Ganymede were fashioning instruments of warfare and building a fleet of space-ships to carry them to their intended victims. It was a religion with them; they could think of nothing else. An unscrupulous scientist of Europa sold himself to them several generations previously and it was this scientist who had made the plans for their space-fliers and had contrived the deadly weapons with which they were armed. He likewise taught them the language of Cos and it now was spoken universally throughout Ganymede in anticipation of the glorious days of conquest.
"You honestly believe them able to do this?" asked Carr, still skeptical after two days of discussion.
"I know it as a certainty," Detis replied solemnly. "It is only during the past generation we have learned of the completeness and awfulness of their preparations. Your people can not combat their sound-ray. With it they can remain outside the vision of those on the surface and set the tall buildings of your cities in harmonic vibrations that will bring them down in ruins about the ears of the populace."
here'll be nothing left for them to take if they destroy all our cities: nowhere for them to live. I don't get it."
"Only a few will be destroyed completely, to terrify the rest of the inhabitants of your worlds. Others will be depopulated by means of vibrations that will kill off the citizens without harming the cities themselves—vibrations which are capable of blanketing a large area and raising the body temperature of all living things therein to a point where death will ensue in a very few minutes. Other vibrations will paralyze all electrical equipment on the planet and make it impossible for your ships of the air to set out to give battle, even were they properly armed."
"Looks bad, Carr," said Mado glumly.