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 struggle 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.

Wait what?...No no no, this is how you do it Erin....

Here's how it is: Earth got used up, so we terraformed a whole new galaxy of Earths, some rich and flush with new technologies, some not so much. Central Planets, thems formed the Alliance, waged war to bring everyone under their rule; a few idiots tried to fight it, among them myself. Hi, I'm Kristopher McMichaels, captain of Sanguine. She's a transport ship, Firefly class, model 4. She needs a good crew: fighters, mechanic. We managed to picked up a decent pilot, (word is her brother is famous) and a bona fide companion. Basically, You got a job, we can do it. Don't much care what it is.

Firefly, post Serenity