I finally got around to listening to this audio book. I do however have a question. When was the dark king set? If it was before Istvaan then surely the night lords were deemed traitors and wouldn't have been sent by the Emperor to Istvaan to stop horus. If it was after then wouldn't they also still be traitors and killed on sight?
Overall I didn't really enjoy these stories. I assume they were written long before the current HH series of books as they don't seem in the same style or quality to me.