Precisely why this had been thought necessary or even desirable was also unknown, though speculation on the matter had preoccupied scholars and experts over the aeons.
With their original builders gone, the people who had attacked the worlds seemingly also permanently missing and the fabled superfluid equally absent, leaving those vast internal spaces linked by the supporting Towers — themselves mostly hollow, though containing twisted webs of structurally reinforcing material, and punctured with portals of various sizes giving access to each of the levels — it had taken almost no time at all for a variety of enterprising species to work out that a derelict Shellworld would make a vast, ready-made and near- invulnerable habitat, after just a few relatively minor modifications.
Gases, fluids — especially water — and solids could be pumped or carried in to fill all or some of the spaces between the levels, and artificial interior ‘stars’ might be fashioned to hang from the ceilings of each level like gigantic lamps. The various venturesome species set about exploring the Shellworlds closest to them, and almost immediately encountered the problem that would bedevil, frustrate and delay the development of the worlds profoundly for the next few million years and, intermittently, beyond; the Shellworlds could be deadly.
It remained unclear to this day whether the defence mechanisms that kept killing the explorers and destroying their ships had been left behind by the worlds’ original builders or those who appeared to have dedicated their entire existence to the task of destroying the great artefacts, but whether it had been the Veil or the Iln — or, as it was now generally agreed, both — who had left this lethal legacy behind, the principal factor limiting the use of the Shellworlds as living spaces was simply the difficulty of making them safe.
Many people died developing the techniques by which a Shellworld might be so secured, and the same lessons generally had to be learned afresh by each competing civilisation, because the power and influence which accrued to a grouping capable of successful Shellworld exploitation meant that such techniques remained fiercely guarded secrets. It had taken an Altruist civilisation — exasperated and appalled at such a selfish waste of life — to come along, develop some of the techniques, steal others and then broadcast the whole to everybody else.
They had, of course, been roundly vilified for such unsporting behaviour. Nevertheless, their actions and stance had, in time, been ratified and even rewarded by various galactic bodies, and the Culture, although far remote in time from these now long-Sublimed people, had always claimed a sort of kinship by example with them.
The civilisations which specialised in making Shellworlds safe and who effectively took part-ownership of their interiors became known as Conducers. Sursamen was unusual in that two species — the Oct (who claimed direct descent from the long-departed Involucra and so also called themselves the Inheritors) and the Aultridia (a species with what might be termed a poorly perceived provenance) — had arrived at the same time and begun their work. It had also been unusual in that neither species ever got a decisive upper hand in the ensuing conflict which, in the only positive aspect of the dispute, at least remained localised to Sursamen. In time the situation within the world had been formalised when the two species were awarded joint protective custody of Sursamen’s access Towers by the then newly formed Galactic General Council, though, importantly, without any stipulation that the two could not contend for increased influence in the future.
The Nariscene were granted full inhabitory rights to the planet’s Surface and overall control of the world, formalising their long-held claim to it, though even they had to defer ultimately to the Morthanveld, in whose volume of influence the system and the world lay.
So Sursamen had been colonised, making it Inhabited, and by a variety of species, hence the Multiply- prefix. The holes in the supporting Towers that might have let gases or liquids vent to lower levels were sealed; some effectively permanently, others with lock complexes that permitted safe entry and exit, while transport mechanisms were installed inside the great hollow Towers to allow movement between the various levels and to and from the Surface. Material in gaseous, liquid and solid form had been moved in over the many millions of years of the planet’s occupation, and beings, peoples, species, species groups and whole ecosystems had been imported by the Oct and the Aultridia, usually for a consideration of some sort or another, sometimes at the behest of the peoples concerned, more often at the request of others.
Interior stars had been emplaced; these were thermonuclear power sources like tiny suns, but with the useful distinction of being anti-gravitative, so that they pressed upwards against the ceiling above any given level. They subdivided into Fixstars and Rollstars, the former stationary, the latter moving across the skies on predetermined routes and on regular, if sometimes — when there were many, of different periodicities — complicated schedules.
The deaths continued, too; long after a given Shellworld had been apparently de-weaponed and made safe, hidden defence systems could wake up centuries, millennia and decieons later, resulting in gigadeaths, teradeaths, effective civicides and near-extinctions as interior stars fell, levels were flooded from above or drained — often with the result that oceans met interior stars, resulting in clouds of plasma and superheated steam — atmospheres were infested by unknown wide-species-spectra pathogens or were turned inexorably into poisonous environments by unseen mechanisms nobody could stop, or intense bursts of gamma radiation emanating from the floor/ceiling structure itself flooded either individual levels or the whole world.
These were the events that gave them the name Slaughter Worlds. At the point that Director General Shoum gazed down upon the dark, colour-spotted face of Sursamen, no mass deaths had been caused by the Shellworlds themselves for nearly four million years, so the term Slaughter World had long since slipped into disuse, save amongst those cultures with exceptionally long memories.
Nevertheless, on a grand enough scale the morbidity of any habitat type could be roughly judged by the proportion that had become Dra’Azon Planets of the Dead over time. Planets of the Dead were preserved, forbidden monuments to globe-encompassing carnage and destruction which were overseen — and usually kept in a pristine, just post-catastrophe state — by the Dra’Azon, one of the galactic community’s more reclusive semi-Sublimed Elder civilisations with attributes and powers sufficiently close to god-like for the distinction to be irrelevant. Out of the four-thousand-plus Shellworlds originally existing and the 1332 unequivocally remaining — 110 in a collapsed state — fully eighty-six were Planets of the Dead. This was generally agreed to be an alarmingly high proportion, all things considered.
Even some of the Shellworlds lacking the morbid interest of the Dra’Azon had a kind of semi-divine investment. There was a species called the Xinthian Tensile Aeronathaurs, an Airworld people of enormous antiquity and — according to fable — once of enormous power. They were the second or third largest airborne species in the galaxy and, for reasons known solely to themselves, sometimes one of them would take up solitary residence in the machine core of a Shellworld. Though once widespread and common, the Xinthia had become a rare species and were regarded as Developmentally Inherently, Pervasively and Permanently Senile — in the unforgiving language of Galactic taxonomy — by those who bothered to concern themselves with such anachronisms at all.
For as long as anybody could remember, almost all the Xinthia had been gathered together in one place; a necklace of Airworlds ringing the star Chone in the Lesser Yattlian Spray. Only a dozen or so were known to exist anywhere else, and seemingly they were all at the cores of individual Shellworlds. These Xinthians were presumed to have been exiled for some transgression, or to be solitude-craving hermits. Presumption was all anybody had to go on here too, as even though the Xinthia, unlike the long-departed Veil or Iln, were still around to ask, they were, even by the standards of the galaxy’s Taciturn cultures, quite determinedly uncommunicative.
Hence the Godded part of Sursamen’s full description; there was a Xinthian Tensile Aeronathaur at its core, called by some of the world’s inhabitants the WorldGod.
Invariably inside the great worlds and sometimes on their exteriors, the shells were adorned with massive vanes, whorls, ridges, bulges and bowls of the same material that made up both the levels themselves and the supporting Towers. Where such structures appeared on the Surface of a Shellworld, the bowl-shaped features had usually been filled with mixtures of atmospheres, oceans and/or terrain suitable for one or more of the many Involved species; the shallower examples of these — somewhat perversely called Craters — were roofed, the deeper usually not.
Sursamen was one such example of a Mottled Shellworld. Most of its Surface was smooth, dark grey and dusty — all the result of being lightly covered with nearly an aeon’s worth of impact debris after systemic and galactic bodies of various compositions, sizes and relative velocities had impacted with that unforgiving, adamantine skin. About fifteen per cent of its external shell was pocked with the covered and open bowls people called Craters and it was the greeny-blue reflected light of one of those, the Gazan-g’ya Crater, that shone through the porthole in the transit facility and gently lit up the bodies of the Grand Zamerin and the director general.
