Produced by Greg Weeks, Mary Meehan and the Online Distributed Proofreading Team at http://www.pgdp.net BRAIN TEASER BY TOM GODWIN _How can a ship travel both forward and backward and sideways in two different directions, be going twice as fast as the speed of light--and still be completely motionless?_ [Transcriber's Note: This etext was produced from Worlds of If Science Fiction, October 1956. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] Carl Engle stood aside as the flight preparation crew filed out of the _Argosy_'s airlock. Barnes was the last; fat and bald and squinting against the brightness of the Arizona sun. "All set, Carl," he said. "They had us to check and countercheck, especially the drives." Engle nodded. "Good. Ground Control reports the Slug cruiser still circling seven hundred miles out and they think the Slugs suspect something." "Damned centipedes!" Barnes said. "I still say they're telepathic." He looked at his watch. Zero hour minus twenty-six minutes. "Good luck, boy, and I hope this space warp dingus works like they think it will." He waddled down the boarding ramp and Engle went through the airlock, frowning a little as he threw the switches that would withdraw the ramp and close the airlock behind him. Barnes' implied doubt in the success of the space warp shuttle was not comforting. If the shuttle failed to work, the _Argosy_ would be on the proverbial spot with the Slug cruiser eager to smear it well thereupon.... Access to the control room was up through the room that housed the space warp shuttle. Dr. Harding, the tall, bristle-browed physicist, and his young assistant, Garvin, looked up briefly as he entered then returned their attention to their work. The master computer, borrowed from M.I.T., stood like a colossal many-dialed refrigerator along one wall. A protective railing around it bore a blunt KEEP OUT sign and it was never left unwatched. Garvin was seated before it, his fingers flitting over the keyboard and the computer's answer panel replying with strange mathematical symbols. The space warp shuttle sat in the middle of the room, a cube approximately two-thirds of a meter along the edge, studded with dials and knobs and surmounted by a ball of some shining silvery alloy. Dr. Harding was talking into the transdimensional communicator mounted beside the shuttle. Engle went on to the computer and waited outside the railing until Garvin finished with his work and turned in his seat to face him. "The last check question," Garvin said. "Now to sweat out the last twenty minutes."