Location: Galactic fringe
Atmosphere: Theoretical nitrogen-oxygen; thick nitrogen smog, high particulate count, high radiation levels, unsuitable for breathing
Body Type: Terrestrial/Venusian
Geist orbits in the life-supporting band of an orange dwarf star; large enough that it isn’t too prone to flare events, but small enough that it can be expected to live longer than most of the rest of the galaxy. Up until relatively recently, it seems to have hosted a thriving biosphere and an intelligent species at some point in the pre-nanotech industrial age of development. Each of the three primary continents had sizable cities across the equatorial region, with smaller settlements in the colder regions away from the tropics and an intricate web of transit systems linking them.
This ended sometime in the last century, when something prompted a massive exchange of nuclear weaponry and possible early antimatter weapons, wrecking the planet for habitability. The scope of the exchange is staggering, even by the threatened exchanges of Earth’s Cold War timeframe; enough material was irradiated and lifted into the upper atmosphere to plunge the planet into a nuclear winter that it’s only just beginning to emerge from, as well as scarring the atmosphere to produce thick blankets of nitrogen oxides that have prolonged the winter and rendered the atmosphere unbreathable even in areas largely untouched by the actual exchange.
With the level of saturation from radiation present, no surviving life has yet been found, but there are a great many examples of the alien biosphere that have failed to rot in the aftermath. As such, biologists from the inner and outer system are all clamoring to get radiation-shielded morphs and gate time to Geist in order to study a biosphere frozen by planetary death. Some hypothesize that life should remain in well-insulated locations – deep underground, or in the deepest ocean trenches, but at best these will be single-celled organisms highly adapted to surviving in their hidden niches. Given time, they’ll likely repopulate the planet after the radiation levels have fallen far enough.
The chief interests of Geist are to xenobiologists interested in the biosphere and xenoarchaeologists looking to explore the ruined cities, but a few hypercorps have launched a venture to claim one of the ruined alien cities and turn it into a massive AR game for the sufficiently wealthy, simulating post-apocalyptic scenarios for their customers to be delighted and horrified by. Ozma and Firewall also have an interest here, with a mutual non-aggression pact among the agents in place, as they look for whatever might have triggered the world-ending exchange of weaponry. No one on either side wants to say it, but there’s a fear that whatever caused the TITANs might have happened here as well – and a fear that it might still be around to be carried back by the other explorers.
Fortunately for the people of the Sol system, the root cause of the nuclear apocalypse that visited Geist is a chance mutation of a fungus that wasn’t particularly compatible with transhuman biology in the first place. The natives of the world lived in symbiosis with it, the fungus helping them digest certain foods and extracting some nutrients in return; near the end of their lives it would begin to form fruiting bodies under their carapaces and erupt once they were dead. The co-evolution of the sapient Geists and the fungus means that nearly every settlement had a structure for sky burial rising from the middle of the settlement, and most medical facilities kept cultivated fungus in among their infants to ensure they’d grow up properly.
The mutation, when it happened, caused the fungus to mistake certain neurochemicals for nutrients needing digested, causing the slow onset of hallucinations and intense paranoia among sufferers. As Geists preferred to follow leaders who showed signs of strong personality over other factors, most of the influential leaders of society either came to lead when the paranoia became manifest or were infected by contact with the original victims. All it took was a hallucination-induced launched of a single nation’s nuclear arsenal to set off terrified and paranoid reprisal strikes, ending up with the entire world doomed to extinction within a few days.
Records of these events still exist, in some bunkers under major cities where the last of the Geists slowly died of deprivation in the aftermath. Anyone who finds and translates them has a fortune in credits and rep awaiting the discovery.