There are numerous instances throughout the book that represent the external conflict between two people. Dana and Rufus, for example, have a complicated relationship that is full of both physical and emotional conflicts. Rufus lies to Dana on multiple occasions, such as when he promises to send letters to Kevin but never does. Their conflict also turns physical during multiple instances. The most poignant moment of physical violence is probably at the end of the novel, where Rufus attempts to rape Dana, Dana stabs Rufus, and Rufus attempts to force Dana to stay in the past, resulting in the loss of Dana's arm.
Other characters that illustrate external conflicts are Tom and Dana, Tom and Rufus, and Alice and Rufus.
Another important conflict which is illustrated in the novel is Dana's internal conflict, whereby she struggles with the knowledge that her relationship with the past is a complicated one. On one hand, she must save Rufus in order to secure her ancestral lineage. On the other hand, she has to live with the knowledge that she is helping and saving the life of a slave-owning man who abuses and rapes those same ancestors she is trying desperately to protect.
A third conflict that arises in the novel is Dana's conflict with nature. In this case, nature refers to the process of time travel as it exists within the novel. Dana has no control over when she travels back in time and very little warning that it will happen. Thus, Dana is constantly in conflict with her destiny—she has no choice in what is happening to her, and her participation in fate's scheme is completely involuntary. Still, she has no choice but to go along with it despite the obvious threat to her safety it poses.