Back on earth, every culture had different names for them. Some called them spirits, phantoms, demons, ancestors, or any plethora of names. Yet, the colonists have taken to simply referring to them as the "presence". They started popping up over a decade ago, and now have become a common occurrence. We didn't know what to make of these beings at first, but some believe it is a sign of things greater to come. They populated the fringe as a nuisance at first.
Messing with objects, scaring people, haunting buildings, and making the scary stories we told our children. Now it's like with every passing year they are growing in number, and some of them are getting angrier. About two years ago one of our scientists realized the truth. These things aren't extraterrestrial lifeforms, but us...something is trapping us here when we die. To make matters complicated Earth went silent back in 1986, and the other colonies are too far away to be of any meaningful help. We are out here all alone, a planet of a million people with nowhere to go within our lifetime.
The government doesn't want to abandon the planet either. Its a remarkable success story of rapid terraformation, and to make matters complicated we don't exactly have enough ships for one million people. So some have taken to simply mass-producing drugs to negate the more disturbing aspects of the presence. Most citizens are too doped up to notice the color of the planet has shifted to black and white or that the night cycle lasts twice as long as day resulting in automated greenhouses keeping our agricultural output from total collapse. As of now, 97% of the planet is suffering from some symptoms of a variety of mental illnesses, and all we can do is dispense emotion or stability pills to make things slightly better for them.
Our people are going to bed, and not waking up. The morgues are filling up day by day with a sprinkling of people, but our scientists estimate in four years every single human on the planet will be dead. Yet, all hope isn't lost as some come back from death they are changed by their experience. They have access to unnatural abilities that science cannot explain, and maybe the light in the ever-expanding darkness of the colony. We believe these "catalysts" to be the best, and last hope against the force keeping us here, and perhaps even changing things for the better.
Some of our worst-off citizens dream of him, they call him the "wanderer", the "ragged king", or the "avatar of undeath". His goals are unknown, and his ambitions unclear, but his will binds the souls of all humanity, and even other organic lives into that of the presence. His spawn rules over the presence and feeds off the negative emotions being generated. Defeating them might just get the ragged king's attention, but this is the only speculation that seems to have any solid evidence. Regardless there is much work to be done in little time as possible.