Pellenne - Geography: Pellenne is a large planet consisting primarily of high-purity unprocessed iron. The iron is not mixed in with rocky ore, or locked below a crust; rather improbably, the entire world appears to be the cooled core of a far larger former planet. It has a thin atmosphere, which at surface level has been heavily polluted and is barely capable of supporting human life. For this reason, human society on Pellenne is almost entirely subterranean. The planet is riddled with gigantic tunnels, most over a kilometre wide and some much larger. All run for hundreds or even thousands of kilometres in meandering, apparently random courses through the world. Some drop vertically from the surface to unfathomable depths, while others form lazy spirals that slowly meander towards the core over tens of thousands of kilometres. All eventually lead downwards. The tunnels appear to have been cut through the iron during some ancient era, using vast boring machines that have now vanished. There has been much speculation as to the source of these channels; the official explanation is that the tunnels are wonders of the Dark Age of Technology, created by the legendary first Askellian settlers during Mankind’s distant times. However, some have pointed to the difficulty of accurately dating the passages; there is also quiet speculation in some quarters that they are far, far older and date back millions of years to some unspecified pre-human culture. The planet’s gravity hovers around one Holy Terran standard; despite the planet’s vast size, this implies that much of its mass may have been removed by whatever created the vast tunnel network that pervades the world.The planet’s unusually elevated radiation levels, atypically, do not appear to derive from the Pellennian system’s own star, but from the planet itself. Radiation levels increase with proximity to the core; at the surface they are raised, but tolerable. In the lowest tunnels they can become quite lethal. The source of the radiation has never been satisfactorily explained, and few are anxious to journey into the lower depths to discover it. Given this, the iron mined on Pellenne should be highly radioactive; however, this is surprisingly not the case. While the iron exhibits high levels of radiation at depth near the core, it somehow loses this quality as it is brought to the surface in a phenomenon not fully understood by the Adepts who have studied it.Such an environment is inimical to human habitation, and as such the planet’s surface outposts and extensive subterranean cities are well-protected with Void Shields and other protections to ward against the horrific effects of rad-corruption. However, much to the dismay of the planet’s long-term inhabitants, mutation rates among the population remain unusually high, even within the richest and best-shielded noble enclaves. Why this should be the case is a growing concern to senior figures within the world’s ruling classes. Some have suggested that the mysterious radiation source deep at the planetary core emits energies undetectable by the traditional rad-augurs, energies which have the effect of mutating human genetic material. The preachers of the Adeptus Ministorum cry out that high mutation rates are a sign not of some physical or genetic taint, but of a spiritual malaise brought about by lack of faith in the Emperor. Certain Inquisitors worry that the truth of the matter lies somewhere between these two extremes, and fear that at the heart of the planet lies some object or being which is somehow twisting the planet’s human inhabitants into new forms.