Evelyn said nothing. For five miles the plane fled as if in panic. Evelyn clung to the filigree side of the cockpit. The city dwindled behind them. Then Aten climbed steeply. Tommy was looking keenly at the glittering thing which propelled the ship. It seemed like a crystal gridwork, like angular lace contrived of glass. But a cold blue flame burned in it and Tommy was obscurely reminded of a neon tube, though the color was wholly unlike. A blast of air poured back through the grid. Somehow, by some development of electro-statics, the "static jet" which is merely a toy in Earth laboratories had become usable as a means of propelling aircraft. Back they swept toward the Golden City, five thousand feet or more aloft. The ground was partly obscured by the hazy, humid atmosphere, but glinting sun-reflections from the city guided them. Soaring things took shape before them and grew swiftly nearer. Tommy spoke again, busily loading the automatic rifle with explosive shells. Aten swung to follow a vast dark shape in its circular soaring, a hundred feet above it and a hundred yards behind. Wind whistled, rising to a shriek. Tommy fired painstakingly. * * * * * The other plane zoomed suddenly as a flash of blue flame spouted before it. It dived, then, fluttering and swooping, began to drift helplessly toward the spires of the city below it. "Good!" snapped Tommy. "Another one, Aten." Aten made no reply. He flung his ship sidewise and dived steeply before a monstrous freight carrier. Tommy fired deliberately as they swept past. The propelling grid flashed blue flame in a vast, crashing flame. It, too, began to flutter down. Tommy did not miss until the fifth time, and Aten turned with a grimace of disappointment. Tommy's second shot burst in a freight compartment and a man screamed. His voice carried horribly in the silence of these heights. But Tommy shot again, and, again, and there was a satisfying blue flash as a fifth big ship went fluttering helplessly down. Aten began to circle for height Tommy refilled the magazine. "I'm bringing 'em down," he explained unnecessarily to Evelyn, "by smashing their propellers. They have to land, and when they land they're hostages--I hope!" Confusion became apparent among the hostile planes. The one Yugna ship was identified as the source of disaster. Tommy worked his rifle in cold fury. He aimed at no man, but the propelling grids were large. For a one-man ship they were five feet in diameter, and for the big freight ships, they were circles fifteen feet across. They were perfect targets, and Aten seemed to grasp the necessary tactics almost instantly. Dead ahead or from straight astern, Tommy could not miss a shot. The fleet of Rahn went fluttering downward. Fifteen of the biggest were down, and six of the two-man planes. A sixteenth and seventeenth flashed at their bows and drifted helplessly.... * * * * *