The Ruin Ring formed a slim dense halo three kilometres thick, seventy kilometres broad, orbiting five hundred and eighty thousand kilometres above the gas giant Mirchusko.  Its albedo was dismayingly low; most of the constituent particles were a dowdy grey.  A haze of small particles could be found up to a hundred kilometres outside the main band in the ecliptic plane; dust mainly, flung out from collisions between larger particles.  Such meagre dimensions made the Ruin Ring totally insignificant on a purely astronomical scale.  However, the effect it had on the course of human events was profound.  Its existence alone managed to bring the richest kingdom in history to the verge of political chaos, as well as posing the Confederation's scientific community the greatest mystery it had ever known, one which remained unsolved a hundred and ninety years after its discovery.

It could so easily have gone unnoticed by the Royal Kulu Navy scoutship Ethlyn, which investigated the system in 2420.  But system survey missions are too expensive to mount for the crew to skimp on detail even though it is obvious there is no terracompatible planet orbiting the star, and naval captains are chosen for their conscientious nature.

The robot probe which Ethlyn fired into orbit around Mirchusko performed standard reconnaissance fly-bys of the seven moons above a hundred and fifty kilometres in diameter (anything smaller was classed as an asteroid), then moved on to analyse the two rings encircling the gas giant.  There was nothing extraordinary or even interesting about the innermost: twenty thousand kilometres broad, orbiting three hundred and seventy thousand kilometres out, the usual conglomeration of ice and carbon and rocky dust.  But the outer ring had some strange spectrographic lines, and it occupied an unusually high orbit.  Ethlyn's planetary science officer raised the probe's orbit for a closer look.

When the achromatic pictures relayed from the probe's optical sensors began to resolve, all activity on board the Ethlyn came to an abrupt halt as the crew abandoned their routine to assess the scene.  The ring which had the mass of a modestly sized moon was composed entirely of shattered xenoc habitats.  Ethlyn immediately deployed every robot probe in its inventory to search the rest of the system, with depressingly negative results.  There were no other habitats, no survivors.  Subsequent searches by the small fleet of Kulu research ships which followed also produced a resounding blank.  Neither could any trace of the xenoc race's homeworld be found.  They hadn't originated on any planet in the Ruin Ring's system, nor had they come from any of the surrounding stars.  Their origin and death were a complete enigma.

The builders of the wrecked habitats were called the Laymil, though even the name wasn't discovered for another sixty-seven years.  It might seem that the sheer quantity of remnants would provide archaeologists and xenoc investigators with a superabundance of research material.  But the destruction of the estimated seventy thousand plus habitats had been ferocious, and it had happened two thousand four hundred years previously.  After the initial near-simultaneous detonation a cascade of secondary collisions had begun, a chain reaction lasting for decades, with gravel and boulders pulverizing large shell sections, setting off another round of collisions.  Explosive decompression tore apart the living cells of plants and animals, leaving already badly eviscerated corpses to be decimated still further by the punishing sleet of jagged fragments.  And even after a relative calm fell a century later, there was the relentless chafing of the vacuum, boiling surface molecules away one by one until only phantom-thin outlines of the original shape were left.