Affinity

Affinity is a novel by British author Sarah Waters, first published in 1999. It explores a dark period in the lonely life of Margaret Prior, a youngish spinster from a wealthy English family. Margaret begins visiting a women's prison as a means of escaping her own ennui and in the hopes of being a positive role model for the inmates. There she meets a young prisoner, Selina, with whom she becomes infatuated. But it is unclear what the mysterious inmate's motives are...

A film adaptation followed in 2008.

Tropes used in Affinity include:

• Adaptation Distillation: The TV adaptation replaced Margaret realising she is a lesbian after falling in love with her future sister-in-law Helen with Margaret becoming attracted to women after her fiancé tries to rape her, leading to some unfortunate implications.
• Angst
• Butch Lesbian: Ruth Vigers, who successfully passes herself off as Selina's male spirit guide in order to seduce and/or sexually abuse young girls at seances. This also qualifies her as a variant on the Psycho Lesbian trope - Waters (obviously) isn't arguing that lesbianism is evil, but this particular lesbian definitely comes across that way.
• Dark and Troubled Past: most of the characters in the story.
• Driven to Suicide: A year before the novel begins, Margaret attempts a fatal overdose of sleeping medicine after learning that her female lover is planning on marrying her (Margaret's) brother. Margaret's narrative ends with her about to attempt suicide again after she learns that Selina has betrayed and deceived her. This second attempt is implied to be successful.
• Eerie Pale-Skinned Brunette: Margaret is one.
• Gaol Time: Margaret spends a lot of time in Millbank Prison, as does the prisoner in whom she takes an interest.
• Gayngst: The primary source of Margaret's depression, following her ex-lover's marriage to Margaret's own brother.
• Psychic Powers: Selina works as a psychic medium, and claims to commune with spirits.
• Queer Romance: Between Margaret and Selina and Margaret and Helen. Also Selina and Ruth, and (depending on your interpretation) Selina and Mrs Jelf.
• Spooky Seance: Selina works as a spirit medium before being sent to Millbank.
• Victorian Britain: set in this era, and very much characteristic of its darker elements.
• Victorian London