The circle tightened upon a tiny, central park. Spacesuited figures worked furiously under a disperser screen; they were putting the last touches upon an alien projector. No light came to them from without, but they could be seen by the light of their own working floods. Outside of the projector and the disperser, a ring of large detector-coupled MacMillans were dancing from point to point and dropping Terran ships with each point. "Ben!" snapped Maynard. "We'd best get that thing before they finish!" "Right. We'll hit 'em with AutoMacs and keep 'em under constant fire." "No good." "We can't hit 'em through that disperser, but they can't see to hit us." "I know. But there's one thing they don't need sight to hit." "Huh?" "Mephisto III, you idiot. Could you hit Luna from Terra without aim?" "If I had an ephemeris." "What do you suppose they call theirs?" "I--" "Break out a ground force," ordered Maynard. "We're going to take that projector!" * * * * * The Terran fire tripled as the ground force moved ponderously across the intervening yards. A salient point was made, and the sides began to widen. Back and forth the individual sorties went, and as men and machines went up in flaring puffs of fire, the salient moved forward toward the projector. Inside the disperser, the combined Martians and Mephistans worked furiously, though they seemed oblivious to their danger. No signals would enter this barrier, and no living thing could step outside and hope to re-enter. They stepped back from the thirty-foot parabola, and one of them thrust down upon a plunger. Above the parabolic reflector, a thick haze formed. A torpedo succeeded in passing the coupled AutoMacs and raced inside of the disperser and into the haze. It exploded, and its energy added to the forming vortex. The haze thickened, became toroidal, and spread out. Up from a dun color it went, into cherry-red incandescence. Up through the red past yellow into blue and then into flaming white went the color-temperature. Like a close-knit toroid of flaming, white-hot metal, it poised above the projector, moved slightly, and then raced upwards. It passed the disperser, and the screen went up in a flare of white. Into the sky above Mephisto went the toroid, and below it, Terrans swarmed over the projector, fought off the remaining enemy, and held the projector as their objective. The last floods of resistance died as the toroid went into the far sky above. "_Orionad!_" bellowed Maynard. His ship lifted, swooped over him, and lifted him on a tractor. Upward they raced, catching the slow-moving vortex.