"Never mind them!" gasped Manning. "There's somebody inside—" The words died on his lips. In the doorway of the traveler had appeared a big man in civilian clothes. His face was hidden beneath a hood exactly like their own, in his hands was a machine gun, and he was looking at them. "Schwinzog!" Manning recognized the beefy figure. "Sie kennen mich? Aber naturlich—you are the other two time travelers!" The gun's muzzle moved in a peremptory arc. "Remove those masks, please. I want to be sure that it is really you who have come to see me off." Manning wavered, torn by a suicidal impulse to rush the machine gun and get it over with. But despair lamed him. He thought numbly, "Time is immutable after all, and something was sure to stop us from changing what's already happened. The fatalists are right." He bowed his head and slipped off the wired hood; then he could no longer see it or his own hands. He felt still more like a ghost, impotent to stir reality. "Now the invisibility units," ordered Schwinzog. "Throw them in front of you." As Manning and Dugan became visible, the goggling soldiers that surrounded them snapped up their rifles to cover them. Schwinzog pushed back his hood and eyed them with satisfaction. "It is good that you are accounted for—though I was not much worried about you, and I understand you do not know the principle of the Zeitfahrer. And you have brought me two more specimens of the invisibility device, which will be useful for study to the German scientists of four years ago—before they were invented in America." He chuckled at the thought. "You realize, the debacle of Germany, the frightful catastrophe engineered by American cunning—will—never take place. I will see to that—that this now shall be only the illusion of might have been.... As to what will become of you, that is an almost metaphysical problem—I think I will set the Herr Doktor Kahl to work on it, when more pressing affairs have been seen to." "You will do what?" broke in a weakly querulous voice. In the entrance of the time traveler had appeared the hunched figure of Kahl. He blinked at the light; his goatee was tattered and his face twitched. Behind him the massive shoulders of Wolfgang blocked the doorway; he wore a twenty-first century German uniform and an air of contentment that showed him, at least, to have found his niche in the world of the future. Schwinzog half turned. "What I will do