Pete was standing just inside the panel, holding something furry and black in his arms that squirmed in the cold light. When he saw me he uttered a smothered oath. I tugged at my helmet, got it off. "Jim, lad, I was afraid you was a goner!" Pete choked. "You went chasing mirages on the hull. Mirages, Jim!" My jaw dropped. I stood stock still, staring at him, unable to believe my eyes. "It's all my fault!" Pete groaned. "Me and my rantings! Jeebies my foot! Soon as you went out I got to thinkin'. There's a beastie could do it, a little black, furry beastie called a mirage pup! "Sired on Pluto, breedin' on Pluto in the dark an' the cold! Squattin' on its haunches, projectin' thoughts! Makin' 'em look solid and real! Sounds too, though you don't hear the sounds with your ears! "His memories, Jim! Things he's seen himself, long, long ago! We been makin' pets of 'em so long we take 'em for granted. All the old skippers had 'em on their ships." "Oh, Eternity!" I choked. "They can make thoughts look as solid as a cake of ice, Jim! Three-dimensional, like! I figured it this way. There was a girl, about a hundred years ago, took a ship—this ship—out to Saturn! And somethin' happened to the ship. So she went out to fix what was wrong and maybe never came back. Her gravity irons could have slipped—" "No," I said quickly. "She let go deliberately because—it was better that way!" I was staring at the little beast. Take a rabbit, puff it out, paint it black, and give it two huge, spectral, tarsierlike eyes! Give it a purple snout, devilishly long claws. Breed it with a full-blooded Scotch Terrier and you'll get—a Plutonian mirage pup! The little beast whined, then yapped and wagged its tail at me. Its ear stood straight up. It nuzzled Pete's palm. Mirage pups could coat everything over with evanescent images that looked real. They could change the outside as well as the inside of a ship. They could put Saturn beyond the viewpane, instead of Jupiter. Put a girl in the ship who lived once, engrave an image of that girl on your heart so that getting it off would mean a tearing anguish. Yes, a mirage pup could do that because it would have a long memory.