In the historic novel Affinity by Sarah Waters, protagonist Margaret Prior, feeling oppressed by her father's recent death, by her mother's overbearing attitude, and by the burdens of her role in upper-class Victorian society, has recently attempted suicide. As part of her recovery plan, she has undertaken charity work and decides to visit the women prisoners in Millbank Prison. During her visits, she starts to get to know a young and beautiful medium named Selina Dawes who has been sentenced for, as it says outside her gate, "Fraud and Assault" (p. 84). At first, Selina receives Margaret's visit very coldly, sending Margaret running. However, Margaret starts feeling drawn to Selina and begins coming to see her again and again; the more frequently Margaret visits, the more Selina becomes friendly and opens up to Margaret.
The two quickly become fast friends, and the more Margaret sees her, the more she starts to feel that Selina is her "affinity," meaning her soul mate. Their close relationship soon leads Margaret to believe Selina loves her and to agree to help Selina escape Millbank; however, the plan does not go as Margaret was led to anticipate. Instead, she soon realizes that Selina set up the plan to escape with and reunite with her maid, Selina's true love.