Firefly Season 1, Episode 13
Airs: 12:00am - 1:00am on FOX
Saffron (from "Our Mrs. Reynolds") returns - after Mal breaks up her current gig, she convinces him and the crew to help out with a "perfect crime" that isn't. The crime: go to Bellerophon and steal a criminal's prototype laser gun from his collection. The plan: Saffron and Mal sneak in and dump the gun down the trash, bypassing security, and the Serenity crew grab it from the disposal system. Of course, this is Saffron, and it turns out she's married to the crook, Durran, and plans to double-cross Mal. Things don't work out so well and Saffron strands Mal naked in the desert. Fortunately Mal and Inara anticipated a betrayal and set it up so Inara grabs the gun, leaves Saffron behind, and rescues Mal.
Meanwhile, Simon figures out Jayne betrayed them (in "Ariel") and the two have words.