Schwartzmann was gone. Harkness, with the bundle of wet fabric in his hands, glanced quickly about. A door stood open--it was a closet--and the rain-drenched man was hidden there an instant later. But he stepped most carefully across the floor and touched his wet shoes only to the rugs where their print was lost. And he held himself breathlessly silent as he heard the volley of gutteral curses that marked the return of Herr Schwartzmann some minutes later. "Imbecile!" Schwartzmann shouted above the crash of the closing window. "_Dumkopff!_ You have let him escape. "Give me your pistol!" Harkness glimpsed the figure of his recent guard. "Get another for yourself--find him!--shoot him down! A little lead and detonite will end this foolishness!" From his hiding place Harkness saw the bulky figure of Schwartzmann, who made as if to follow where the other man had gone. The pistol was in his hand. Walt Harkness knew all too well what that meant. The tiny grain of detonite in the end of each leaden ball was the same terrible explosive that drove their ships: it would tear him to pieces. And he had to get this man. He was tensed for a spring as Schwartzmann paused. From the wall beyond him a red light was flashing; a crystal flamed forth with the intense glare of a thousand fires. It checked the curses on the other's thick lips; it froze Harkness to a rigid statue in the darkness of his little room. * * * * * An emergency flash broadcast over the world! It meant that the News Service had been commandeered. This flashing signal was calling to the peoples of the earth! What catastrophe did this herald? Had it to do with the Dark Moon? Not since the uprising of the Mole-men, those creatures who had spewed forth from the inner world, had the fiery crystal called!... It seemed to Harkness that Schwartzmann was hours in reaching the switch.... A voice came shouting into the room: "By order of the Stratosphere Control Board," it commanded, "all traffic is forbidden above the forty level. Liners take warning. Descend at once." Over and over it repeated the command--an order whose authority could not be disregarded. In his inner vision Harkness saw the tumult in the skies, the swift dropping of huge liners and great carriers of fast freight, the scurrying of other craft to give clearance to these monsters whose terrific speed must be slowly checked. But why? What had happened? What could warrant such disruption of the traffic of the world? His tensed muscles were aching unheeded; his sense of feeling seemed lost, so intently was he waiting for some further word. "Emergency news report," said another voice, and Harkness strained every faculty to hear. "Highline ships attacked by unknown foe. Three passenger carriers of the Northpolar Short Line reported crashed. Incomplete warnings from their commanders indicate they were attacked. Patrol ship has spotted one crash. They have landed beside it and are reporting....