In order to convert the space opera feel of Septimus into the space horror campaign setting I want it to be, the main change I intend to incorporate is the nature of the Sindavar Extent. The Sindavar Extent or just Extent, as it is commonly referred, started out as a fringe technology cult exploring the edges of the galaxy. Past problems involving artificial intelligence and nanotechnology had resulted in widespread distrust of these technologies and organizations which use them. Since the Extent was just such an organization, most Imperial citizens who were even aware of the group, were generally relieved when they seemingly disappeared about a century ago.
About 10 years ago, an automated signal started broadcasting from the approximate location where the Extent was thought to be headed. It was a short message inviting the people of the galaxy to flee the chaos of the dying Empire and join the Extent in the Septimus worldsphere. It has been repeating constantly since that day. Early colonists who accepted the invitation found Septimus to be a utopia. The capital, Arcopolis, and the other major settlements, known collectively as the Seven Cities, were wonders to behold, although the cloning and nanotech modification practiced by the original inhabitants was difficult for some to accept. Things didn't really start to unravel until the Corruption began. The Extent used alien technology to exert control over ever aspect of life, AIs known as Persona Constructs were enslaved and put to work building the perfect society. But something was wrong. It first started in the cloning clinics. Deformities appeared, clones died. Then the thought control systems began to break down. People began to see the reality of their enslavement. Resistance groups began to spring up. The Extent used harsher and harsher means to exert control. This prompted several groups to cooperate in the execution of Steel Helix, a plan to damage or destroy the central control system of the Persona Constructs. It was a partial success. Though the system was not destroyed, several Personas were freed. The results were catastrophic.
It has been a few years since Steel Helix and there is a sense of a calm before the storm within Septimus. Within the core of Arcopolis, all seems normal. The citizens continue on with their daily lives. Peace has been reestablished and the city has been rebuilt. Beyond the great walls of the arcology, the ruins of the greater metropolis teem with activity as millions scratch out a living among the detritus. Most recent newcomers settle in the Archipelago, a series of planets inside the sphere, where several new stellar nations have risen. Still, no one believes the Extent is beaten. In the days leading up to Steel Extent, many unspeakable atrocities were committed and many technological horrors were unleashed. The Extent demonstrated the extremes to which they were prepared to go to maintain control. Few doubt they would be hesitant to go just as far to regain it.