The same premise often results in very different stories when you give it to different authors at different times. The idea I'd been posting about previously, about a scout contacting a lost colony world, could easily go in very different directions depending upon what specific story you want to tell and how you want to execute the telling.
Which is where I'm at right now. I have a protagonist (see previous post), a deuteragonist (see next post), and a few supporting characters. I'm lacking an antagonist, and an immediate conflict. Answering those questions will depend on the what and how of the story I want to tell.
So, what sort of story are we going for? Well, I'm aiming for something in the "Sword & Planet" vein. That means something needs to go wrong for our scout right off the bat, because otherwise his starship and other such technologies can short-circuit the plot. How to deal with this? That's where a habit I picked up from decades in tabletop role-playing games comes up: Villian-driven plotting. Which means it's time to deal with that antagonist question.
Who would want to prevent contact from off-world, and why? Given the premise--the scout's patron believes this to be a colony formed by distant relations--it would be someone hostile to said relations reconnecting to the interstellar community. Also given that the scout's mission comes as part of a larger plan by his patron, this world is not founded as a dumping ground for undesirables. In short, we're not looking at a prison planet.
So, what sort of colonial operation would be launched at considerable distance? Commercial exploitation is well-known, but this premise implies long-term settlement; commercial colonial administrations are known for being short-sighted and short-lived (plenty of personnel turnover). That, I think, can be ruled out. No, I think we're going to think of something more like lesser sons going into the frontier to get lands of their own- a thing often involving religious or philosophical movements.
There's our conflict source: the colony arose from some need to find open land for a religious community. The patron's family would remain a part of that tradition if it still sought it all these years, and some other incident had to occur to lose it originally. I could go with some malevolence native to the world, but just as likely is someone in the colony seizing power and the cut-off is a consequence of that usurpation.
That's our antagonist: the current leader of that usurpation clique. They fear off-world contact because they tried to take control of the colony and lost; they fear contact because they believe contact brings their enemies reinforcements that would finish them off, so they use what they've got to maintain their isolation.
The deuteragonist has immediate ties to the colonial regime, as a soldier in its military, and has faced the antagonist's minions in a recent war, which gives him a reason to be looking out for things like falling stars (crashing ships) and dealing with strangers. So our start is: scout arrives in-system, antagonist detects scout and forces him down, deuteragonist rescues protagonist from minions, protagonist and deuteragonist swap briefs to escape full stakes on table. Proceed accordingly.
I'd thought I'd do this as a short, but I'm thinking that may not be enough. We'll see.