"I'd rot in prison first," he growled finally, "but for the fact that it would be suicidal to trust such equipment in the hands of morons. A larger generator could extend a Dimension-rift clean to infinity and sooner or later some incompetent fool would swing the beam in operation and slice the universe in half!" And that was how the brass and brains of Allied Military got their big Di-tube generator built. It took three weeks, with Doc superintending and Dora and me doing the work, to set it up and tune it for the test. Doc, being a hard loser, made one last-ditch attempt to argue them out of using the Di-tube. "The mathematical concepts involved in this operation," he told the generals and their white-smocked technical staff, "are obviously beyond the grasp of your stunted intellects. Therefore I shall make shift with your adolescent analogy of the two-dimensional ant, which improbable brute in boring through his sheet of paper would find himself _for the duration of his passage_ in a plane totally alien and untranslatable to terms of his own experience. "Like the ant we are dealing with a wholly new concept--subspace. My calculations show that other dimensions--there is no way of determining how many--lie above and below our own. In short-cutting either adjoining dimension we shall be as utterly out of our accustomed element as the ant in the paper. Moreover the continuum we call subspace is inhabited. Surely even you can see the danger involved?" He was right, of course, but it didn't buy him anything. Nobody ever convinced a full general with that kind of argument. "Proceed with the test," ordered Three-star Corbin. There was nothing else for it. Dora clung to my arm, pressing close enough to make me almost glad of the risk we ran, while Doc obeyed orders. Doc, muttering minor blasphemies into his beard, punched the button that activated the big generator--and loosed catastrophe, as the telepapers later said, on an unsuspecting world. The big Di-tube machine didn't sizzle like the model--it roared. The glowing strain-bubble over the generator built up slowly to a humming orange sphere ten feet across. The cylindrical shaft of nothingness that speared out of the under side helix punched a hole like a mine shaft in the laboratory floor, a vertical tunnel of absolute vacancy that twisted the eyes half out of our heads with its brain-wrenching alienness. The Twisters were out in force, swarming around in the big beam and looking more than ever like inside-out octopuses. They didn't have any eyes, as far as I could see, but I could feel them staring upward, studying us. "_Now_ will you listen to reason?" Doc demanded, and reached for the switch. "I'm going to turn off the beam, before--" Catastrophe stopped him.