The feel of the controls was good to his hands; the ship roared into life. A beautiful little cruiser, this ship of Diane's; her twin helicopters lifted her gracefully into the air. The column of red light had changed to blue, the mark of an ascending area; Chet touched a switch. A muffled roar came from the stern and the blast drove him straight out for a mile; then he swung and returned. He was nosing up as he touched the blue--straight up--and he held the vertical climb till the altimeter before him registered sixty thousand. Traffic is north-bound only on the sixty-level, and Chet set his ship on a course for the frozen wastes of the Arctic; then he gave her the gun and nodded in tight-lipped satisfaction at the mounting thunder that answered from the stern. Only then did he read again the message on a torn fragment of telautotype paper. "Harkness," was the signature; and above, a brief warning and a call--"Danger--must leave at once. You get ship and stand by. I will meet you there." And, for the first time, Chet found time to wonder at this danger that had set the hard-headed, hard-hitting Walt Harkness into a flutter of nerves. * * * * * What danger could there be in this well-guarded world? A patrol-ship passed below him as he asked himself the question. It was symbolic of a world at peace; a world too busy with its own tremendous development to find time for wars or makers of war. What trouble could this man Schwartzmann threaten that a word to the Peace Enforcement Commission would not quell? Where could he go to elude the inescapable patrols? And suddenly Chet saw the answer to that question--saw plainly where Schwartzmann could go. Those vast reaches of black space! If Schwartzmann had their ship he could go where they had gone--go out to the Dark Moon.... And Harkness had warned Chet to get their ship and stand by. Had Walt learned of some plan of Schwartzmann's? Chet could not answer the question, but he moved the control rheostat over to the last notch. From the body of the craft came an unending roar of a generator where nothing moved; where only the terrific, explosive impact of bursting detonite drove out from the stern to throw them forward. "A good little ship," Chet had said of this cruiser of Diane's; and he nodded approval now of a ground-speed detector whose quivering needle had left the 500 mark. It touched 600, crept on, and trembled at 700 miles an hour with the top speed of the ship. There was a position-finder in the little control-room, and Chet's gaze returned to it often to see the pinpoint of light that crept slowly across the surface of a globe. It marked their ever-changing location, and it moved unerringly toward a predetermined goal. * * * * *