Calixis Sector - Sibellan Society: Hive Sibellus is Scintilla's power centre and every noble house on the planet seeks to have its own estate on the hive spire. These estates form an extraordinary riot of architectural styles, from stern fortresses to gilded pleasure palaces. The spire is constantly growing, the new estates built on the remains of the old, and so a Sibellan noble house must constantly strive to embellish its own estates to keep up.Antiquity is everything in Hive Sibellus. A family draws prestige from the number of ancestral generations it can trace and even the newest estates look like age-weathered bastions of tradition. Hive Sibellus' nobles are intensely competitive and demonstrate their superiority through the magnificence of their estates as well as the antiquities they collect, from artefacts excavated from the deserts and jungles of Scintilla to works of art from across the Imperium. Most estates conceal a high-security gallery or museum, which sometimes holds extremely valuable and illegal items, like xenos artefacts or even dangerous proscribed texts.The streets of the hive spire are constantly busy. Hive Sibellus' noble fashions are spectacular, impractical and perpetually changing, and the nobles travel the streets of the spire accompanied by large retinues of servants whose primary role is to look impressive. The streets in the spire are very safe thanks to the large private armies that guard every estate and the efforts of the Enforcers of the Magistratum to man checkpoints, which regulate the people coming in and out of the hive spire. Violence in the spire, apart from trials by combat and sanctioned duels, is rare -- the crime that most nobles fret about is burglary, since their collections of artworks and relics are so important to them. Tales of impossibly-skilled cat burglars are a staple of Hive Sibellus' folklore and many of those tales are true, since there are a great many things worth stealing in the spire of Hive Sibellus.Hive Sibellus' middle hive is dominated by manufactoria devoted to heavy production and the enormous blocks of cheap, warren-like housing for the manufactoria workers. The traditions of the hive spire filter down to the middle hive, with many hivers collecting curious objects to beautify their meagre homes, aping the extraordinary fashions of the spire nobles or even keeping crudely stuffed dead relatives. The middle hive's manufactoria and tenement blocks are built among layers of compressed mansions and statuary, making it a confusing and dark place of collapsed finery.Somewhere deep amongst the fragments of vast statues and toppled remains of great temple-mansions, the middle hive becomes the underhive. Composed of countless compressed layers of the city above, Hive Sibellus' vast underhive is impossible to navigate and prone to frequent collapse. Underhive settlements huddle in the few stable areas, separated from one another by endless deadly warrens where hive-quakes and cave-ins are a constant threat. Many underhive settlements are completely isolated, their inhabitants hunting underhive vermin to survive and having no idea that there is a hive city above them at all. It is not unknown for nobles of the spire to sponsor heavily-armed expeditions into the underhive to dig up coveted artefacts from Scintilla's past or to explore the tombs of a family's distant ancestors.