Anna and Sebastian opens as a much older Anna grapples with aging and a disorienting change in the relationship with her long-time lover, Sebastian. Years earlier he hired a woman who, unlike Anna, was still of child-bearing age to conceive. Now, eighteen years later, the daughter, attempting to live alone as an adult, is sexually assaulted and trafficked. At this point, the novel explores the effects of assault and trafficking not only on Sebastian's daughter, but on Anna, who adapted to the unusual paternity, and on Sebastian, who did not bargain for the suffering he experiences as a father.