"Couldn't get too curious. No." "Damn." "Why?" "Somehow, Nora is tied up in this. On my side." "Okay, I'm going to follow one other lead. Take it easy, Paul, and give the physicists hell." "I'll try." * * * * * "I will begin at the beginning," smiled Paul, wishing he had the air of a professional lecturer and the literary ability of an author, "space was first conquered by rocket propulsion. Eventually a base was established on Luna and the space stations set up. Operating in space, the physicists discovered the supervelocity drive, which like electricity, was used long before people began to understand it. "The rocket is a clumsy device and ill-adapted to anything but limited, professional use. But the superdrive made space travel practical for the ordinary man. Space was truly conquered then, and today men live on Venus and on Mars. Precariously and uncomfortably, but they live there. Men have spread throughout the solar system, working in mines and medicinal farms and jungles. Their tenure of employment is dictated by the rigors of life on these inimical planets of Sol. "With the superdrive, explorers chased through the nearer galaxy, seeking a planet suitable for colonization. While most stars have been found to have planets, there was not one found that filled the bill until they located Neosol and Neoterra, both of which resemble Sol and the earth to a fine degree. "Radio linked the colonies of Sol, and after Neosol was colonized, radio linked its spread-out colonists. "Forty years ago, Carrington discovered the Z-wave, an outgrowth of the superdrive. Then the instantaneous Z-wave replaced the slow radio transmissions that required teletype and code communications, and voice to voice contacts prevailed throughout the solar system, and throughout the system of Neosol. "But the Z-wave did not cross the gulf of interstellar space, and years of experimentation followed, all of which failed. Then, twenty years ago, Chadwick Haedaecker suggested the theory now known as Haedaecker's Theory, which tended to show that the Z-wave propagated because of the fields of force generated in the central cores of stars. Since that date, only desultory attempts have been made to test the Z-wave in deep space. Experimentation had stopped, for all practical purposes. About the only people who have given the matter much thought are students of theory, and a couple of hardy souls like myself, who--I have been accused and of which I must admit--hoped to become rich and famous by making some extraordinary discovery. "I will now advance the idea that I hope will be eventually known as Grayson's Principle. "The basis of Grayson's Principle is that the Z-wave will not propagate between points that have not previously been linked by electromagnetic waves!"