Affinity is a 1999 historical fiction novel by Sarah Waters. It is the author's second novel, following her debut Tipping the Velvet. Set during 1870s Victorian England, it tells the story of a woman, Margaret Prior, who is haunted by a shadowy past and in an attempt to cure her recent bout of illness and depression, begins visits to the women's wards of Millbank Prison. Whilst there she becomes entranced by the spiritualist Selina Dawes, with whom she becomes obsessed and begins an inappropriate relationship. Written as an epistolary novel, the story alternates as a series of diary entries written by both main characters.
