Flies from the Amber

Forty light years from earth, the colonists on the world of Unua have somehow managed to keep civilization struggling on, despite twice daily earthquakes and technology lagging far behind that of the mother planet. But now an Unuan mining expedition has discovered an alien mineral they name centrokrist—a stone of incomparable beauty. Yet when the Earth scientists at last arrive to investigate, they find a phenomenon eclipsing this discovery. For this double-sunned solar system is nestled ri...