After the Earth was used up, we found a new solar system and hundreds of new Earths were terraformed and colonized. The central planets formed the Alliance and decided all the planets had to join under their rule. There was some disagreement on that point. After the War, many of the Independents who had fought and lost drifted to the edges of the system, far from Alliance control. Out here, people struggled to get by with the most basic technologies; a ship would bring you work, a gun would help you keep it. A captain’s goal was simple: find a crew, find a job, keep flying.
Brought together through circumstance when they were captured by human traffickers, they are now in possession of a less than new starship, attempting to keep their margins black (or not deep in red) as possible while avoiding those who are hunting them.