"O. K., Mart," he finally announced. "They exist, all right, and I can detect 'em. Look here," and he pointed to a tiny receiver, upon which a small lamp flared in brilliant scarlet light. "Are they sending them?" "No, fortunately. They're coming from our bar. See, it shines blue when I put a grounded shield between it and the bar, and stays blue when I attach it to their detector ray." "Can you direct them?" "Not a chance in the world. That means a lifetime, probably many lifetimes, of research, unless somebody uses a fairly complete pattern of them close enough to this detector so that I can analyze it. 'Sa good deal like calculus in that respect. It took thousands of years to get it in the first place, but it's easy when somebody that already knows it shows you how it goes." "The Fenachrone learned to direct fifth-order rays so quickly, then, by an analysis of our fifth-order projector there?" "Our secondary projector, yes. They must have had some neutronium in stock, too--but it would have been funny if they hadn't, at that--they've had intra-atomic power for ages." Silent and grim, he seated himself at the console, and for an hour he wove an intricate pattern of forces upon the inexhaustible supply of keys afforded by the ultra-projector before he once touched a plunger. "What are you doing? I followed you for a few hundred steps, but could go no farther." "Merely a little safety-first stuff. In case they should send any real pattern of sixth-order rays this set-up will analyze it, record the complete analysis, throw out a screen against every frequency of the pattern, throw on the molecular drive, and pull us back toward the galaxy at full acceleration, while switching the frequency of our carrier wave a thousand times a second, to keep them from shooting a hot one through our open band. It'll do it all in about a millionth of a second, too--I want to get us all back alive if possible! Hm--m. They've shut off their ray--they know we've tapped onto it. Well, war's declared now--we'll see what we can see."