"Steve, I simply can't get used to such a prodigious moon! Look at the stripes, and look at that perfectly incredible...." A gong sounded and they both jumped to their feet and raced madly into the _Hope_. The ultra-receiver had come to life and the sounder was chattering insanely--someone was sending with terrific speed, but with perfect definition and spacing. "That's Brandon's fist--I'd know his style anywhere," Stevens shouted, as he seized notebook and pencil. "Tell me what it says, quick, Steve!" Nadia implored. "Can't talk--read it!" Stevens snapped. His hand was flying over the paper, racing to keep up with the screaming sounder. "...ymede all x stevens ganymede all x stevens ganymede all x placing and will keep sirius on plane between you and tellus circle fifteen forty north going tellus first send full data spreading beam to cover circle fifteen forty quince suggests possibility this message intercepted and translated personally I think such translation impossible and that he is wilder than a hawk but just in case they should be supernaturally intelligent...." Stevens stopped abruptly and stared at the vociferous sounder. "Don't stop to listen--keep on writing!" commanded Nadia. "Can't," replied the puzzled mathematician. "It doesn't make sense. It sounds intelligent--it's made up of real symbols of some kind or other, but they don't mean a thing to me." "Oh, I see--he's sending mush on purpose. Read the last phrase!" "Oh, sure--'mush' is right," and with no perceptible break the signals again became intelligible. "... if they can translate that they are better scholars than we are signing off until hear from you brandon." * * * * * The sounder died abruptly into silence and Nadia sobbed convulsively as she threw herself into Stevens' arms. The long strain over, the terrible uncertainty at last dispelled, they were both incoherent for a minute--Nadia glorifying the exploits of her lover, Stevens crediting the girl herself and his two fellow-scientists with whatever success had been achieved. A measure of self-control regained, Stevens cut off his automatic sender, changed the adjustments of his directors and cut in his manually operated sending key. "What waves are you using, anyway?" asked Nadia, curiously. "They must be even more penetrating than Roeser's Rays, to have such a range, and Roeser's Rays go right through a planet without even slowing up." "They're of the same order as Roeser's--that is, they're sub-electronic waves of the fourth order--but they're very much shorter, and hence more penetrating. In fact, they're the shortest waves yet known, so short that Roeser never even suspected their existence." "Suppose there's a Jovian space-ship out there somewhere that intercepts our beams. Couldn't they locate us from it?"