I woke up as nervous as a Martian juju. This was it. Listless was sitting at the control box, when I came in from breakfast, fingers ready to press the buttons tied into the plate chambers. Murphy was running around the ship putting up filters over observation ports at my suggestion. They still didn't have an inkling of what I was shooting at. "O.K.," I choked. "Let 'er go." Listless pressed the main contact. The box warmed up with a steadily rising hum. The little lights blinked on and the main panel showed the location of each asteroid. I read the figures off to him and his fingers ran over the board more nervously than his toes would ever go. The dots of light on the indicator panel started slowly in motion. They built up speed, flashing faster and faster around the two focal points I had calculated. "Take an observation," I told Murphy, sweating. He shot a glance out of the bow port, filter in his hand, ready to slap it on. "No stuff yet," he reported. The asteroids were revolving dizzily now. Suddenly a tremor passed through the ship. "There she goes!" I screamed. Murphy's eyes bugged out against the transparent plate. "There's something out there, Doc," he yelled. "Light by all that's uncontrollable. It's getting bigger. And brighter!" Lomack was still madly balancing the orbits, speeding up the asteroids like rocks on strings. A burst of brilliance came streaming through the forward observation. Murphy put up the filter. I sat back with a breath of deep, deep relief. "There you are, boys," I wheezed. "One sun as per specification. Completely under control. Lomack, if your fingers were fast enough we could use it for a blinker. All you have to do is control the speeds the right way." * * * * * Listless had established equilibrium by now, and threw over the box to automatic. He went back to the store room and brought out the last case. We sat down and drank to my health. Several times. And to my brain. Often. "How'd you figure it?" asked Murphy when the back pounding was over. "Boys," I said in a superior tone, "it's really very simple." Murphy threw the opener at me, so I got down to business. "You both know the rudiments of Einstein, don't you?" I asked. They nodded in agreement. "Well, you know the theory of space warp. Not the way the plates work but the fundamental proposition. Gravity does not exist as such. I mean there is no actual attraction between the sun and the planets. The sun is of such tremendous mass that it warps space elliptically around it in such a way that any body of a given mass and speed just has to travel a certain way. Instead of speaking of orbits, you might say, that, like marbles, the planets fall into certain grooves and there they stay." I stopped for a long one.