Ash was never informed that he and La Motte had a child.As the Great Storm of 1987 strikes England, all the interested modern parties come together at Ash's grave, where they intend to exhume documents buried with Ash by his wife, which they believe hold the final key to the mystery."In short, the whole book is a gigantic tease – which is certainly satisfying on an intellectual level" but, "Possession's true centre is a big, red, beating heart.It's the warmth and spirit that Byatt has breathed into her characters rather than their cerebral pursuits that makes us care".Obscure scholar Roland Michell, researching in the London Library, discovers handwritten drafts of a letter by the fictional eminent Victorian poet Randolph Henry Ash, which lead him to suspect that the married Ash had a hitherto unknown romance.
"Yet more impressive are in excess of 1,700 lines of original poetry".
At the same time, their own personal romantic lives – neither of which is satisfactory – develop, and they become entwined in an echo of Ash and La Motte.
The stories of the two couples are told in parallel, with Byatt providing letters and poetry by both of the fictional poets.
Reading them, Maud learns that rather than being related to La Motte's sister, as she has always believed, she is directly descended from La Motte and Ash's illegitimate daughter.
Bailey thus is heir to the correspondence by the poets.
Possession is set both in the present day and the Victorian era, contrasting the two time periods, as well as echoing similarities and satirising modern academia and mating rituals.