"Send for me," grinned Hank. "I like this period o' your'n okay, Bud. But you won't get in no more messes like that. Not if you tone down the speed o' that gadget o' your'n, like I told you to. "My figgerin'? Why, it was just plain, dumb hosslogic, that's all. The tip-off come when we started whiskin' faster an' faster by the moment toward that there planet in our path. "Y'see, we was in a negative universe. We decided that. But whut we overlooked was the simple, logical fact that in a negative universe all natcheral physical laws ought to operate in reverse! "Way I see it, we just happened across that planet by accident. An' had we been content to let well enough alone, we'd never have come anywhere near it! It would have shunted us off on its own account!" I said, "What? How do you figure--" Biggs exclaimed, "_I_ see! In our positive universe, it is axiomatic that all objects attract each other in direct ratio to their masses. But in a _negative_ universe--" "They'd repel each other," nodded Hank. "Right. I guess we was dumb, though. We done the _one_ thing we shouldn't have ever done. Put out anti-gravs and repellor-beams against the upstart planet! Which was the one thing calc'lated to drag us to it! In this backward universe, mathematics an' physics worked in reverse. Anti-gravitational beams attracted, and propellors repelled!" Biggs sighed. "And I've always considered myself a logical man! What you did was turn on every available, ounce of energy and thrust the _Saturn_ at full speed _toward_ the planet, realizing that for every action there is an equal and opposite reaction, and that the planet's terrific repelling force would throw us completely back out of negative space--is that it?" Hank gazed at him admiringly. "I reckon," he said softly, "that's about it. But you sure explain it purty...." * * * * * So why go on? We got into the machine, then. Hank and Helen and I. And again things began flickering. And at the last minute, I remembered there was something I wanted to ask Biggs, but it was too late then, for there came another moment of giddy spinning, fireworks in my eyes and butterflies in my tummy, and then-- We were back in my apartment. And it was broad daylight, but my radio was still on, as I had left it, and already it was blatting a news item about how Prof. Hallowell had inexplicably returned. There'd be other flashes later, I knew. And a lot of explaining to be done to an unbelieving public.... * * * * * Then I said, "Damn!" "Yeah?" said Hank. "Why for, Jim?" "Something I meant to ask Biggs and forgot. But you can tell me, I guess. One thing I never did understand, was why Biggs got so excited when he found out you and Helen were not married. What difference did _that_ make? Why did that cause him to show such great confidence that we were going to pull out of our jam?" Hank flushed. "Well, you see--" he hesitated.