Dana and Rufus have an extremely complex relationship because when Dana travels into the past, she is a slave while Rufus is the plantation master, but she also later finds out that she is biologically related to Rufus. Dana's relationship with Rufus is typical of slave-master relations in many ways.
Dana is an adult woman living in the 1970s when she is inexplicably transported to the antebellum South. As a black woman, she is automatically considered a slave in the past, even though she is a professional writer in her "real life" in 1976. While she is a slave on the plantation, she is mistreated and beaten, as the other slaves are. However, because of her historical knowledge and intermittent returns to the 1970s between trips to the past, she is better equipped to survive the hardships she must endure. Even though Rufus is very young when Dana first arrives, on later trips, he has grown up and become the master of the plantation. He can often be cruel, exerting the full force of his power. He rapes another female slave and even attempts to rape Dana.
Also late in the novel, Dana discovers that Rufus is one of her ancestors. This obviously creates an inner conflict because Dana knows how flawed he is. Her situation, though, was very common during slavery. Masters often raped their female slaves and impregnated them. Therefore, many children were the products of the union of a slave and her master. Dana, living in the 1970s, is removed from the immediacy of this truth, but when she is thrust into the past, she must face it head-on. Despite the complexity of her feelings, Dana ends up killing Rufus, and she and her husband Kevin agree that Rufus's death is for the best.