The two globes were now a quarter of a mile apart, and the distance was steadily growing. Even as Mona watched the gap increased until almost a mile separated the two great worlds. "Do you see?" cried Fort, fairly squirming in his seat. "Do you see what I've done, Mona?" "I've taken Ernol and his friends--the bunch I rescued from the prison--and put them to work. Put them to work digging a tunnel! We've been flying above that tunnel just now. It runs--from the contact to the cannon--the bottom of the cannon, Mona! "When Powart's shot was fired, the recoil--the kick--broke the contact! Understand? Do you see it?" Mona stared in dull wonder. When she found voice it was strangely flat and commonplace. "Yes, but--I don't see how the recoil could separate two worlds as large as Hafen and Holl!" Fort chuckled breathlessly. "Your forget something. You're thinking only of the gravitation; you're forgetting the centrifugal force." Hafen and Holl, by their daily rotation--around the contact as a center--were always tending to separate. That recoil was just enough to turn the balance; they'll never touch again. "And what's more," he rushed on, "Powart's shot is sure to miss! The recoil threw the cannon out of line. Hafen had already mooved before the projectile left the gun. Powart--has failed!" Suddenly the surgeon wheeled upon the athlete. "Boy, we're headed in the wrong way! We'll land in Holl, not in Hafen!" "Who wants to live in Hafen now?" he shouted, clinging desperately to his controls. The craft was tossing in the newly created air-currents. "Don't you see? "I've cut Hafen from Holl forever! The workers aren't to be slaves any longer; they're to have their world to themselves, to use entirely for their own benefit; not for the owners! "And the owners--back there--they're going to have their own world, too, just as they've always insisted! But from now on it's to be their farm, too, and their factory; they've got to get along without Holl from now on. "Mona--the commission wouldn't allow evolution, and the workers wouldn't listen to revolution! So I've given them--devolution!" "What?" she cried. "I've given them devolution. I've given the race of man--a fresh start." But Mona was scarcely listening. "Turn back!" she screamed. "I want to go back to my home! I don't want to live in Holl. Turn back, I tell you!" Fort's face went white. He looked up at her appealingly. "You don't mean that, Mona! Say you don't!" "I do! I want to go back!" She glanced down at the ever-widening gap. "Hurry! Turn back, or I'll do it myself!" Fort gazed straight into her eyes for an instant; then, his face whiter than ever, he brought the craft to an abrupt halt in mid air. He looked at his watch for the last time, and said, in a strangely hollow voice: "Just as you wish, Mona. There's plenty of time to get back before the air gets too thin in the gap.