I'm looking for the name of a series of space opera novels I read some time ago, probably between 2003 and 2010.
- It may have been published quite a few years before I read it, I don't think it was new at the time.
- I borrowed the novels from the local library, but I can't find them in its catalogue.
- I think the covers were fairly dark and plain, though there may have been some artwork on them.
- There was a totalitarian empire that controlled most planets, possibly ruled by a queen.
- There was no mention of Earth, the solar system or other real planets, the setting was completely fictional.
- There were people with psychic/psionic powers, referred to as something like "psi". These people were second-class citizens or slaves.
- Spaceships were used to travel between worlds. I'm not sure what kind of FTL technology they had, if any.
- Beyond the edge of the empire was some kind of "dark space", where there was no light.
- There were some horror themes: When travelling in dark space in one of the novels, a ships crew experienced strange thoughts and hallucinations. I remember finding this quite scary at the time.
Does anyone know which series this could be?
This isn't a duplicate of this question, since the two questions are about different parts of the same series (the first and second episodes).