Emma Donoghue examines how desire between women in English literature has been portrayed, from schoolgirls and vampires to runaway wives, from cross-dressing knights to contemporary murder stories. She looks at the work of those writers who have addressed the "unspeakable subject," examining whether same-sex desire is freakish or omnipresent, holy or evil, as she excavates a long-obscured tradition of (inseparable) friendship between women, one that is surprisingly central to our cultural history. Donoghue explores the writing of Sade, Balzac, Hardy, Wilkie, Sayers, Highsmith and more to reveal the half-dozen contrasting girl-girl plots that have been told and retold over the centuries; the paranormal identities assigned to women who desire other women; the ubiquity of same-sex attraction in crime fiction; and the contemporary narratives of coming out privately and publicly.Inseparable is a revelation of a centuries-old literary tradition -- brilliant, amusing, and until now, deliberately overlooked.