In the far-distant future, Captain Malcolm "Mal" Reynolds is a renegade former brown-coat sergeant, now turned smuggler & rogue, who is the commander of a small spacecraft, with a loyal hand-picked crew made up of the first mate, Zoe Warren; the pilot Hoban "Wash" Washburn; the gung-ho grunt Jayne Cobb; the engineer Kaylee Frye; the fugitives Dr. Simon Tam and his psychic sister River. Together, they travel the far reaches of space in search of food, money, and anything to live on.
Five hundred years in the future, a renegade crew aboard a small spacecraft tries to survive as they travel the unknown parts of the galaxy and evade warring factions as well as authority agents out to get them.
Firefly is set in the year 2517, after the arrival of humans in a new star system and follows the adventures of the renegade crew of Serenity, a "Firefly-class" spaceship. The ensemble cast portrays the nine characters who live on Serenity.