We return to Firefly today. Persephone however has seen more action in the show. It's a common touch down point for the crew to resupply and pick up a job.
Captain Malcom Reynolds has Serenity land on Persephone early on in the series, a planet ruled by the Union of Allied Planets but close to the border worlds so there is a huge divide between classes that Persephone becomes famous for. Most importantly, it's the place where Mal picks up a few characters. That is, Simon and River Tam, Shepherd Book, and Lawrence Dobson.
This is where the crew of Serenity for the show comes together. And what a crew it is.