Imagine walking up a street and having the sky literally burst open over your head; imagine invaders pouring down and you have-- Harwood's Vortex By Robert Silverberg [Transcriber's Note: This etext was produced from Imagination Stories of Science and Fantasy April 1957 Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] The vortex bubbled up out of nowhere, hung shimmering in the air in front of me, glistened and gleamed brightly. There was a whirlpool of twisting currents in the air, and I wavered dizzily for a second or two while the Invaders poured through the newly-created gulf. Then someone had me by the hand, someone was pulling me away. Leading me inside the house, behind a screen, safe from danger. I didn't understand what had happened. I was numb with shock, half-blinded by the brightness. I felt Laura near me, and that was all I cared to think about. After a couple of minutes, I opened my eyes. "What was that?" I asked weakly. "What happened?" Two minutes before, I had been approaching the Harwood house, impatient to see Laura, untroubled by the world around me. And suddenly-- "It was Daddy's experiment," Laura half-sobbed. "It--it worked!" "The old crackpot," I said. "The dimensional gulf--at last? I wouldn't believe it, if I hadn't nearly fallen into it!" She nodded. "I saw you staggering around out there. I got out front just in time to--to--" I held her tight against me, while she unloaded some of her anxiety. She sobbed for a minute or two, not trying to say anything. I looked uneasily out the window. Yes, it was still going on. Right in front of Abel Harwood's house, the vortex was open--and coming up through it were what we later knew as the Invaders. Globes of light, radiant and intangible, floating up out of nowhere and ringing themselves in the air like so many loathsome jellyfish. "Why doesn't he close it?" I asked. "Those things are still coming through! Laura, where's your father?" "I'm right here," said a cold, business-like voice from behind me. I turned and saw Abel Harwood's husky frame in the door. "What do you want of me?" Harwood asked. "Do you see what's going on out there?" He nodded. "So?" "Those _things_ out there--what are they? What are you letting into the world, Harwood?" "It's an experiment, young man." He crossed his arms over his dressing-gown. "Would you mind leaving my house, now?" "Daddy!" "You keep out of this, Laura." He turned to me. "I've asked you to leave my house. I don't want you meddling in my experiments any more."