Synopsis: From the back cover of the DAW first edition: "They had built Utopia on Earth at last. Ten thousand years in the making... They built it on a platform that covered the polluted surface of the old world, turned men's eyes away from the unsolved problems of the bad old days and brought their shining new cities up into the perpetual sunlight. But down there, in the lamplit "sky" of the old surface, life had persisted. Men existed, and semi-men, and things that never were men... and nobody in the sunlight above knew of them - until disturbing dreams began to intrude and visions bothered a few sensitive minds. One man investigated. One man went down to that forgotten basement of the Earth and thereby uncovered the grave of the world that was - and let its transformed phantoms glimpse the light above."