Jean-Jacques Annaud’s 1986 adaptation of Umberto Eco’s novel is set in a 14th-century abbey where monks keep turning up dead. Sean Connery plays William of Baskerville, a Franciscan with a talent for puzzles. Christian Slater plays his young novice, Adso of Melk. The film is a thriller that asks for patience, and it repays some of that patience but not all of it.

The source is no small thing. Eco’s 1980 debut novel, set in 1327, has sold more than 50 million copies. It won the Strega Prize in 1981 and the Prix Médicis Étranger in 1982, and Le Monde placed it 14th on its list of the hundred books of the century. A film of The Name of the Rose has to decide what to keep from a book that is half murder mystery and half seminar on semiotics, biblical analysis and medieval scholarship. Annaud keeps a great deal, and that choice explains both what works and what drags.

What works first is the story’s geography. A library that visitors may not enter, a labyrinth of shelves, and a hidden room called the finis Africae, named after the presumed edge of the world: these are ideas that make a mystery feel physical. The deaths follow a pattern of dread. A monk is found in a vat of pig’s blood with black stains on his tongue and fingers. Another is found drowned in the bathhouse, with the same stains. The herbalist Severinus, who says he has found a strange book, ends up dead in his laboratory with his skull crushed by an armillary sphere. Each death tightens the screws, and the poison clue keeps the plot moving whenever the talk threatens to stall it.

Connery is the reason to watch. He gives William a dry wit and a calm authority, the manner of a man who was once an inquisitor and has since decided that reasoning is kinder than torture. He is never in a hurry. When he shrugs off a theory, you believe he has already thought of three better ones. The role needs that confidence, because the whole film rests on the idea that William fights a shadowy conspiracy armed only with his intelligence, and that intelligence has to be visible in every scene.

The trouble is pace. The murders arrive in the first act, but the investigation proceeds through long conversations about doctrine. The abbey is host to a disputation between Pope John XXII’s side and the Franciscans over apostolic poverty, and the film spends real time on it. In a novel, such passages can be savoured at leisure. On screen they sit like stones in the middle of a thriller. The debate between William and the elderly Jorge de Burgos over whether laughter is permissible is clever on the page, and Feodor Chaliapin Jr. gives it weight. Even so, it works as an idea rather than as drama, and the plot waits while the characters talk.

The direction is competent rather than daring. Annaud tells the story in a straightforward classical manner and seldom takes a risk with it. For a film so concerned with secrets, it is oddly reluctant to be strange. I wanted a stronger sense that the abbey itself was hiding something, and I did not quite get it. The resolution, once the culprit is exposed, arrives with less force than the buildup promised. It is coherent, and faithful to the book’s logic, but it plays more as an explanation than as a shock.

The supporting cast is uneven, mostly through no fault of the actors. F. Murray Abraham is a chilling Bernardo Gui, the Grand Inquisitor who arrives with the pope’s legation and quickly arrests Salvatore, played by Ron Perlman, for witchcraft and heresy. Gui is a man who treats certainty as a virtue and doubt as an offence, and Abraham plays him with exactly that cold assurance. Michael Lonsdale as the Abbot, William Hickey as Ubertino da Casale and Elya Baskin as Severinus all have the right faces for their parts. But the story hurries them along, and some of them are reduced to a function. Slater, as Adso, is overshadowed by Connery for much of the film. That is partly the nature of the part, since Adso is mostly an observer, but he does little to make it more than that.

The themes are the book’s, and they remain interesting: who controls knowledge, who decides what may be read, and whether laughter and doubt are threats or signs of health. The film states these ideas often and sometimes too openly. Characters deliver them in speeches, when a gesture or a silence would carry them better.

This is a respectable, serious film with a very good central performance and a gripping premise. It is not a great one. If you come for Connery and for the pleasure of watching a clever man dismantle a conspiracy, you will be well served. If you want the book’s depth or a tighter thriller, you will find the film admirable but a little cold.