ASANTHUS is another ruined world, but unlike Idmon, the entire history of Asanthus is still available for study.  Two minerals native to the planet have the unique property that the scratch marks easily made by one upon the other are extremely resistant to weathering or accidental removal.  So, archival-quality documents exist from the earliest days of human life on Asanthus, engraved on sheets of these minerals.  They tell the story of a bountiful new colony that quickly grew to occupy many cities, each with an official hall of records.  Micro-engraving permits extensive records that take up relatively little space, though some are "illuminated" with detailed borders and illustrations.  The tragic development that led to the downfall is likewise recorded, though initially as light-hearted mentions of a ridiculous new fad.  The freak discovery of a novel propulsion technology led to the immediate popularity of so-called "Super-Boots".  After a few months of teenagers flying low over every rural acre, the novelty was already starting to fade when farmers discovered that this year's crops were simply dead in the ground.  To this day nothing grows almost everywhere on Asanthus, and its cities are now almost entirely empty.