How long is it?
576 pages in the Vintage 1991 paperback edition.

About 11 h 30 min · at 30 minutes a day, about 24 days
Estimated from the page count of this edition. Dense books can take longer than the estimate.
In a London library, underemployed scholar Roland Michell discovers draft letters suggesting that Victorian poet Randolph Henry Ash had a secret love affair. His search leads to poet Christabel LaMotte and Maud Bailey, a specialist in her work. Following the correspondence through England and Brittany, Roland and Maud protect their discoveries from rival academics while their growing connection complicates their own relationships.
Intellectually dense but often playful, the literary mystery alternates the modern investigation with the Victorian love story. Long passages of invented poetry, letters and diaries require as much attention as the search itself, so the pace regularly slows for reading within the reading. The intertwined romances include occasional on-page sex without graphic detail.
Collected’s assessment, not reader ratings. Complexity runs from 1 (least demanding) to 5 (most demanding).
Canonical
576 pages in the Vintage 1991 paperback edition.
Vintage · 1991 · Paperback. ISBN 9780679735908.
About 11 hours 30 minutes at 50 pages an hour, based on the 576-page Vintage edition. Dense books can take longer.
A. S. Byatt was an English novelist, short-story writer, poet, and critic whose fiction brought intellectual inquiry into close contact with narrative. Drawing on Romantic and Victorian literature, she combined realism with fantasy and used dense, descriptive prose to examine art, desire, history, and the ways people interpret one another. Poems, letters, diaries, artworks, and inherited stories often serve as active parts of her fiction rather than as decoration. In Possession, two scholars reconstruct a secret Victorian relationship from scattered documents, turning literary research into both a detective story and an inquiry into who may claim authority over another life. Her shorter fiction similarly refashioned traditional forms: the adult fairy tales in The Djinn in the Nightingale's Eye place enchantment within modern arguments about creativity, marriage, power, and freedom.