Similarly went the next two in each fortress, and the next--then Radnor's two projections were cut off sharply as the Chloran's impenetrable zone of force went on, and that fortress, all its beams and forces inoperative, floated off into space. Siblin and his partner were more fortunate. When the amœbus commanding their prey threw in his zone switch nothing happened. Its source of power had already been destroyed, and the two Valeronian images went steadily down the line of converters, in spite of everything the ragingly frantic monstrosities could do to hinder their progress. The terrible beam of destruction held steadily upon that fortress by the beamers in Valeron's mighty dome had never slackened its herculean efforts to pierce the Chloran screens. Now, as more and more of the converters of that floating citadel were burned out those screens began to radiate higher and higher into the ultra-violet. Soon they went down, exposing defenseless metal to the blasting, annihilating fury of the beam, to which any conceivable substance is but little more resistant than so much vacuum. There was one gigantic, exploding flash, whose unbearable brilliance darkened even the incandescent radiance of the failing screen, and Valeron's mighty beam bored on, unimpeded. And where that mastodonic creation had floated an instant before there were only a few curling wisps of vapor. "Nice job of clean-up, boys--fine!" Seaton clapped a friendly hand upon Radnor's shoulder. "Anybody can handle them now. Better you take a week off and catch up on sleep. I could do with a little shut-eye myself, and you've been on the job a lot longer than I have." "But hold on--don't go yet!" Radnor exclaimed in consternation. "Why, our whole race owes its very existence to you--wait at least until our Bardyle can have a word with you!" "That isn't necessary, Radnor. Thanks just the same, but I don't go in for that sort of thing, any more than you would. Besides, we'll be here in the flesh in a few days and I'll talk to him then. So long!" and the projection disappeared. * * * * * In due time _Skylark Two_ came lightly to a landing in a parkway near the council hall, to be examined curiously by an excited group of Valeronians who wondered audibly that such a tiny space ship should have borne their salvation. The four Terrestrials, sure of their welcome, stepped out and were greeted by Siblin, Radnor, and the Bardyle. "I must apologize, sir, for my cavalier treatment of you at our previous meeting." Seaton's first words to the coördinator were in sincere apology. "I trust that you will pardon it, realizing that something of the kind was necessary in order to establish communication."