Mercedes

Mercedes has a comfortable life, but you can see in her eyes that she can't let go of her past. Even her attempts at cheerfulness are tinted with sadness.

Mercedes is really the characater that drives this plot. She's not particularly active in the story line, but much like Julia from Cowboy Bebop, she's at the core of everything. I guess some would see her as the prize, but to a great extent she's just the victim of circumstances and these happen to be very dire circumstances.