Affinity is set in Victorian England; the story of an upper-class woman, Margaret , who becomes an official "Visitor" to a woman's prison; however, she becomes emotionally attached to one of the inmates, Selina . As the story progresses through Selina's shady background, and Margaret's dislike of her home life; a plot to break out of the prison develops. But just what the plan is, and who calls the shots is yet to be discovered.