I saw a world of yellow seas lapping at endless shores of mud. There was a fuming pit, where liquid sulphur bubbled up from some inner source, filling an immense natural basin. The Gool clustered at its rim, feeding, each monstrous shape heaving against its neighbors for a more favorable position. I probed farther, saw the great cables of living nervous tissue that linked each eating organ with the brain-mass far underground. I traced the passages through which tendrils ran out to immense caverns where smaller creatures labored over strange devices. These, my host's memory told me, were the young of the Gool. Here they built the fleets that would transport the spawn to the new worlds the Prime Overlord had discovered, worlds where food was free for the taking. Not sulphur alone, but potassium, calcium, iron and all the metals--riches beyond belief in endless profusion. No longer would the Gool tribe cluster--those who remained of a once-great race--at a single feeding trough. They would spread out across a galaxy--and beyond. But not if I could help it. The Gool had evolved a plan--but they'd had a stroke of bad luck. In the past, they had managed to control a man here and there, among the fleets, far from home, but only at a superficial level. Enough, perhaps, to wreck a ship, but not the complete control needed to send a man back to Earth under Gool compulsion, to carry out complex sabotage. Then they had found me, alone, a sole survivor, free from the clutter of the other mind-fields. It had been their misfortune to pick a psychodynamicist. Instead of gaining a patient slave, they had opened the fortress door to an unseen spy. Now that I was there, I would see what I could steal. A timeless time passed. I wandered among patterns of white light and white sound, plumbed the deepest recesses of hidden Gool thoughts, fared along strange ways examining the shapes and colors of the concepts of an alien mind. I paused at last, scanning a multi-ordinal structure of pattern within pattern; the diagrammed circuits of a strange machine. I followed through its logic-sequence; and, like a bomb-burst, its meaning exploded in my mind. From the vile nest deep under the dark surface of the Gool world in its lonely trans-Plutonian orbit, I had plucked the ultimate secret of their kind. Matter across space. * * * * * "You've got to listen to me, Kayle," I shouted. "I know you think I'm a Gool robot. But what I have is too big to let you blow it up without a fight. Matter transmission! You know what that can mean to us. The concept is too complex to try to describe in words. You'll have to take my word for it. I can build it, though, using standard components, plus an infinite-area antenna and a moebius-wound coil--and a few other things...."