It’s a worthwhile movie, possessing some appealing gothic elements, though it feels drawn out, moves at a sluggish pace, is overly dark, and doesn't closely follow the original book. I recently watched this film and found myself enjoying it. It's a reimagining of an earlier version from 1972, both inspired by an older historical novel with the same title, published in 1796 by Matthew Gregory Lewis, who may have been influenced by republican ideals and strong opposition to religious authority coming from Revolutionary France. The story unfolds during the early years of the 17th century, within the Spain ruled by the ultra-Catholic Habsburg Kings. A baby left at a Capuchin convent grows into Friar Ambrósio, an esteemed preacher who attracts large audiences. However, things change with the arrival of Valério, a new monk whose face is always concealed due to burns. As time passes, we learn that this newcomer isn't what he appears to be. The narrative is agreeable and has a gothic feel, even though it’s set during the Counter-Reformation rather than in medieval times. As someone who studies history, I think the film takes too many liberties with reality, including fanciful details like the story of the pregnant nun left for dead. The original novel portrays this character differently, giving her a more compelling and interesting storyline that makes Agnes one of the heroes of the earlier work. While I appreciated the oppressive atmosphere and the pleasingly dark tone, the movie is undeniably slow-moving. Being a French production, most of the actors speak French and deliver performances that are restrained and elegant rather than overtly dramatic. I was impressed by the work of Joséphine Japy and Déborah François, with the latter being alluring without relying on revealing her body. Geraldine Chaplin also seemed well-cast in her brief appearance. Roxane Duran and Frédéric Noaille didn’t have enough screen time to truly showcase their abilities. Ultimately, it feels almost like a one-actor film: Vincent Cassel carries the movie and provides a mature, accomplished, and consistently intense portrayal. The cinematography contributes to the heavy atmosphere, limiting what we can see to just a few points of light. I understand that director Dominik Moll intended this style, seeing it as a stylistic choice, but for me, it was an issue and felt tiring. There are scenes completely shrouded in darkness, showing only part of an actor’s face illuminated by very faint light. Along with the excessive darkness, the film's pace is painfully slow—even someone using a walker would move faster. The music, composed by Alberto Iglesias, is well-done and serves its purpose effectively.

Source on TMDB