They fired a peculiarly destructive shell which, it was thought, would be most effective against the light Xenephrene structures--Graff's space-vehicles and his flying platforms. There also was the crimson barrage projector to be assembled and mounted. And a fighting force of some two hundred planes, whose pilots and gunners were all to be black-garbed and goggled. It would take a week or two for these preparations. The attack would be made against Graff's Brazilian base; it was found now that his mid-African force had withdrawn and returned to Brazil. All the Xenephrenes were concentrated there; it was exactly what the earth leaders most desired. There was a week of complete inactivity from Graff. Scouting planes, ordered not to approach too close, reported that his barrage seemed deepening in color and sound; and he had placed a red radiance overhead. His inactivity seemed threatening to the Miami authorities. All the earth preparations were going hurriedly forward in Miami. It seemed an ominous lull, while both sides were preparing. Graff, it was hoped, did not know what the earth was planning. He would be taken completely by surprise. One great surprise rush, by night. They believed in Miami that they would be ready by about August 20. The world publics waited, expectant. The news of the arrival of weapons from Garla was hushed and suppressed lest by some chance it get to Graff. The world public was fed with radio propaganda; the invaders had withdrawn from Africa because they feared the earth's attack; they were concentrated in Brazil--their power to harm earth was lessening; soon the earth forces would fall upon them; destroy them. Or perhaps even now, the Xenephrenes were planning to withdraw from earth, as they had before. Upon such opiate as this the public was fed. It is always so in times of war! Newspapers printed pages of learned technical explanation of what would happen, by all the laws of mathematics and logic, when once the world powers went into battle. Newspaper experts analyzed the scientific facts from every angle, reaching always the same triumphant solution--experts who knew no more of the real facts than did their readers. And the public waited expectant. Freddie and Dan, chafing at their forced inactivity, persuaded the Miami authorities to let them try Freddie's heat ray, in advance of the main earth attack. It was Freddie's plan, and father also agreed to its merit. Graff would be suspicious at this long silence from his enemy--just as Miami was daily growing more suspicious of him. Freddie's projector could create, with a two-mile range, a heat of some three hundred degrees Fahrenheit; it had a three-mile range, if the heat were concentrated to a six-foot striking area. Graff's barrage was vertical. Its horizontal area of danger was no more than five or six hundred feet.