Haven't watched the movie (I just know from the synopsis it's not very faithful to the novel, what with all those biker dudes) but boy is the novel bleak! It's especially depressing because the main character is so unhappy and downtrodden, even though her job is to lure humans to the slaughterhouse.
My phrasing was clumsy but also spoilerish. Trust me it's not natural that she'd be depressed because she led people to their deaths (consider farmers), and in fact, that's not the root of her depression!
Let me rephrase for clarity: even though her job is to lead people to the slaughterhouse, making her a "villain" in a more traditional story, we nonetheless empathize with her and feel her pain, since she is an outcast, unhappy with her life and downtrodden by her own people. "Even though" she leads people to their deaths, she lacks any real agency in it; she's pressed into that life.
