It was August 24th, 2037. For three days, now, seven of the eight great combat-squadrons of the United Nations Fighting Forces had been prisoners inside a monstrous transparent dome of force. There was a financial panic of unprecedented proportions in the great financial districts of New York and London and Paris. Martial law was in force in Chicago, in Prague, in Madrid, and in Buenos Aires. The Com-Pubs were preparing an ultimatum to be delivered to the government of the United Nations. Thorn and Sylva were hunted fugitives within the inner dome of force, which protected the red rocket-ship from the seven combat squadrons it had imprisoned. Newspaper vendor-units were shrieking, "Air Fleet Still Trapped!" and a prominent American politician was promising his constituents that if a foreign nation dared invade the sacred territories of the United Nations, a million embattled private planes would take the air. And he seemed not even trying to be humorous! Scientists were wringing their hands in utter helplessness before the incredible resistance of the dome. It had been determined that the dome was a force-field which caused particles charged with positive electricity to attempt to move in a right-hand direction about the source of the field, and particles charged with negative electricity to attempt to move in a left-hand direction. The result was that any effort to thrust an external object into the field of force was an attempt to tear the negatively charged electrons of every atom of that substance, free from the positively charged protons of nuclei. An object could only be passed through the field of force if it ceased to exist as matter--which was not an especially helpful discovery. And--Thorn Hard and Sylva were still hunted fugitives inside the inner dome. * * * * * The sun was an hour high when the helicopter appeared to hunt for them by day. After the first time they had never dared light a fire, because Kreynborg in the helicopter searched the hills for a glow of light. But this day he came searching for them by day. Thorn had speared a fish for Sylva with a stick he had sharpened by rubbing it on a crumbling rock. He was working discouragedly on a little contrivance made out of a forked stick and the elastic from his parachute-pack. He was haggard and worn and desperate. Sylva was beginning to look like a hunted wild thing. Two hundred yards from them the most formidable fighting force the world had ever seen littered the earth with gossamer-seeming cellate wings and streamlined bodies at all angles to each other. And it was completely useless. The least of the weapons of the air-fleet would have been a godsend to Thorn and Sylva. To have had one ship, even the smallest, where they were would have been a godsend to the fleet. But two hundred yards, with the dome of force between, made the fleet just exactly as much protection for Sylva as if it had been a million miles away.