You can definitely tell this book was written by an academic. The level of extreme detail is fitting of an author determined to prove her argument (even though she's not really arguing anything here.) Her thoroughness also gives her away. The whole story is fully explained, no unanswered questions are left for the reader to interpret.
Possession is both a mystery and a love story. It's about taboo relationships reaching higher levels of intensity than traditional ones. There are two main sets of lovers: Randolph Henry Ash and Christabel LaMotte, two poets from the 19th century and Roland and Maud, two modern academics studying the two poets respectively. When Roland comes across some unsent letters linking Ash to LaMotte he seeks out Maud to uncover the history of the poets' connection. The connection is so important because it could possibly change all existing interpretation of not only the poets' lives but their poetry as well. Roland and Maud begin their search pretty casually, but the subject matter is so significant to the scholars it would affect that other academics begin sniffing along the trail. The mystery here is at the center of the world for these characters even though, comparatively, it's not big mystery. Each character involved in the quest for answers brings an additional nugget of information into the story that helps solve things in the end.
The story is primarily told with a modern-day, third person narrator shedding light on the characters and the story. The characters themselves are all lost in such a way that allows this type of narrator to really shed light on every one's inner thoughts and feelings. It adds depth to the story. In addition to the present in the story, letters, poems, journal entries, and flashbacks are all used to reveal bit and pieces of the plot. Even with all these genres, the story never feels jumpy. I will admit that some parts were harder to get through than others because of the style (I wasn't a huge fan of the poetry,) but I finished the book satisfied with the story itself and how it unfolded.
It's hard to say whether or not I'd recommend this book. It's really for a very specific audience if you ask me, the kind of person who still loves classical literature and the suspense of the taboo from the 19th century. It's definitely not a summer, beach read.