One of the wonderful things about writing a series is that, once set, the same backdrop applies to the stories that follow – the Universe remains the same, the places, familiar characters, politics and wars are all there – that saves a lot of time and a lot of thought and is a real bonus because only the plots have to come from scratch.
That said, I have discovered the other side of the coin which, strangely, is added complexity. A series (if you’re lucky) grows, branching outwards in all directions. The backdrop might remain the same, but it won’t be long before you’re taking one set of characters and bringing them together with another set of characters, or playing one location against another.
I’m extra lucky, I have a whole galaxy at my disposal (lots of planets) and two warring empires, each much bigger in scope to the Terran new kids daring into space colonization. There are characters in there I have grown very fond of and don’t want to lose, so their stories will loop back into new ones as they unfold, bringing complexities I had not considered, each section and story intermeshed and spiraling around the others – much like the galaxy they are in.