From the back cover of the Berkley Medallion paperback: A young man finds he has extrasensory talents. Then he discovers that others have them, too - though few as powerful as his. And then comes an appalling discovery: he finds that if he cannot master these PSI powers he will certainly go mad. And no one has ever mastered them. His desperate battle to find the secret of the power leads him to a source utterly alien - and awesome in its implications for Earth's fate....
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