Neil LaBute’s fourth film, “Possession,” marks his entry into the ranks of mature Hollywood directors. His previous films (“In the Company of Men,” “Your Friends and Neighbors” and “Nurse Betty”) have been proficient and intelligent, but now he has combined his keen directorial vision with rich cinematography and lush scenery. Except for the presence of frat-boyish Aaron Eckhart, a fellow BYU grad who has appeared in each of LaBute’s films, “Possession” looks every bit like the elegant English romantic drama it attempts to be.

In fairness, Eckhart does well here. His captain-of-the-football-team delivery suits his character, an American named Roland Mitchell who works in London as a research assistant to a professor of Victorian poetry. Roland stumbles across some relatively torrid letters written by Randolph Henry Ash, the 19th-century poet in whom his boss specializes. What’s noteworthy is that Ash had a wife to whom he seemed completely devoted. Furthermore, the letters seem to be addressed to the poetess Christabel LaMotte, a devout lesbian. If Roland can prove this correspondence — which no scholar has ever discovered before — actually took place, it will rock the literary world. (Admittedly, the literary world is one that is easily rocked.)

He seeks out Dr. Maud Bailey (Gwyneth Paltrow), who is far prettier than her frumpy name and dowdy demeanor would suggest. She is a cold fish and an expert in Christabel LaMotte; surely combining these two worlds of knowledge can lead them to the bottom of the mystery. And surely a romance between the two researchers is also in the offing. How can it not be, with musty old manuscripts and gooey love poems at the center of their work?

Based on A.S. Byatt’s novel and adapted by LaBute, David Henry Hwang and Laura Jones, the story plays out much like a mystery, with Roland and Maud finding clues and following leads that, in my opinion, often materialize too easily and conveniently.

It is all interspersed with scenes from Ash and LaMotte’s lives, those roles being played by Jeremy Northam and Jennifer Ehle, respectively. A period piece only about those two would have been grand to watch, especially as played by such accomplished actors. Paltrow and Eckhart are very good as the modern-day researchers, but their romance seems obligatory. There is no indication that the 150-year-old affair they’re studying led them, inspired them or brought them together; they just wound up together, the same as they would if they’d been working on any other project (at least in the world of movies, where co-workers of the opposite sex always fall in love).

Considering this is a film about people doing research, it’s amazing how well LaBute maintains the audience’s attention. But the old, dead romance is far more interesting than the present-day one, with more emotional impact and dramatic weight. However, the gorgeous English countrysides and personable, slyly witty performances makes this a worthwhile endeavor, regardless of which half of the movie you feel more attached to.

B- (1 hr., 41 min.; PG-13, one mild profanity, brief strong sexuality.)