what role does Dana play in the story in relation to Rufus?

Dana learns what slavery is really like as she grows close to her fellow slaves, but also maintains a relationship with Rufus, who, as he grows older, becomes more difficult to tolerate due to his prejudices and controlling tendencies. She has to kill Rufus to prevent him from raping her, which sends her definitively back to the present. She struggles with the ramifications of this decision, but ultimately has a greater understanding of the relationship between past and present.