A reformist pope who courageously leads the Catholic Church to controversial changes should be played by an actor with an impressive presence. There is such a Pope in Conclave – he appears at the beginning of the film and is the real catalyst of the drama – but he is played by an actor, Bruno Novelli, with no other credits and no exceptional screen aura. The role is very difficult: when the action begins, this pope is dead and the actor has nothing to do but lie still. All the more reason for this character, who still has a firm grip on his followers and allies even in death, to be played by a global star with irrepressible charisma – a quality with religious connotations – so that the mere sight of him, briefly, inspires awe.

This may seem like a small casting issue, but it shows what this film is missing. Its plot is as clever as its imagination is ponderous, its themes are as serious as its approach to them is dull. “Conclave,” an adaptation of a novel by Robert Harris, is a talk-thriller set in the Vatican as the College of Cardinals gathers to elect a new pope. Leading the papal election is Cardinal Thomas Lawrence (Ralph Fiennes), the reform-minded dean of the College of Cardinals who is also a close friend of the late Pope's close associate and foreign minister, Cardinal Aldo Bellini (Stanley Tucci), a sharp-tongued, highly principled liberal and the natural successor to the papacy. But other cardinals have also campaigned for the office, including Nigerian Cardinal Joshua Adeyemi (Lucian Msamati), whose hostility to homosexuality angers liberals; Goffredo Tedesco (Sergio Castellitto), an outspoken reactionary who loudly rails against modern freedoms and wants to restore the Latin Mass; and Joseph Tremblay (John Lithgow), the late Pope's chosen camerlengo, or chamberlain, a seemingly impartial bureaucrat who has fulfilled his responsibility for announcing the Pope's death and done so in a way that arouses suspicion.

Because of Lawrence's reformist preferences and personal loyalties, his management of the trial proves to be more than merely ceremonial or administrative. The drama is based on the vote itself – the elaborate formalities by which the cardinal electors, of which there are one hundred and twenty-one (in real life), cast their votes, with a two-thirds majority required to determine a winner. Voting takes place in the titular conclave, whose etymology means “with a key,” suggesting the circumstances under which the election is held. The cardinals are sequestered in hotel-like quarters in the Vatican and sequestered like jurors in high-profile trials – isolated from all external media. The most promising candidates, none of whom manage to prevail in the first round, engage in active campaigning, and Lawrence becomes embroiled in political machinations, first attempting to promote Bellini and then, as support for Bellini dwindles, to form a coalition around Tedesco keep away.

The drama revolves around conflicts between sworn duties and moral responsibility, between following rules and faithfulness to a higher law. As with many elections, this October election has its own surprises, and the looming scandals are about the same things that are roiling secular politics – sex and money. The difference is that Lawrence is far from being encouraged to bring such things to light, but rather is obliged by the conclave's media isolation not to investigate the basis of suspicions. But hints of trouble extend to the nuns who work in the Vatican; One in particular (played by Isabella Rossellini) pays a lot of attention. There's another surprise when a new cardinal shows up at the last minute that no one knew about: Vincent Benitez (Carlos Diehz). Benitez is the archbishop of Kabul, and the late pope had appointed him in pectore – that is, in secret – a tactic probably intended to protect him from persecution. He carries a letter of unimpeachable authority certifying his nomination, and his mysterious presence becomes the object of increasing fascination among his colleagues.

In the filming of “Conclave,” Edward Berger (based on a screenplay by Peter Straughan) offers juicy insights into the elaborate rituals of the Vatican, such as the sealing of the late Pope’s door with wax or the old-fashioned paper votes that are placed on a plate and tipped into a container and the mechanisms of generating white and black smoke as a signal to the Vatican observers. Berger clearly enjoys displaying the material and procedural secrets of the Holy See alongside the sumptuous backdrops of the Vatican, but he does so with an ahistorical curiosity—with the anecdotal imagery of a travelogue. The drama, of course, depends on how all the coalitions and maneuvers develop and who is elected in the end. The inconclusive first round suggests that many rounds will be necessary. And while anyone who's seen “Twelve Angry Men” knows how such a plot works, the tension that arises as the backroom intrigues get wilder and the plans get more daring is effective, if simple.

The filmmaking maintains a steady, methodical poise throughout – to match the simplicity of everything but the tension. Berger delights in showing the mundanity of the cardinals' extraordinary duties and portraying the incense-shrouded mysteries of religion as a professionalized and rigorously practical field whose highest representatives are as tenacious and worldly as secular politicians. However, this slight skepticism is at odds with the story itself, which ultimately suggests, somewhat respectfully, that spiritual enlightenment guides those who take souls as their mission. This remarkable statement makes it all the more disheartening that, in a film about building coalitions and changing hearts and minds, little time is spent on discussion among the many cardinals outside the inner circle of officers and candidates. about the upcoming decisions and what they think about them.

More crucially, the narrative's creamy charm neutralizes the larger themes the film evokes: crises of faith. It's the simmering core of the plot, revealed in a few bars of dialogue and couched in a sermon – and more than one character, the film suggests, might be plagued by such fundamental doubts. The raw material of “Conclave” approaches the grandeur of classic religious cinema, be it the spiritual austerity of Dreyer, Rossellini or Bergman or the anti-clerical fury of Buñuel or Pasolini, but Berger films like a tourist. The superficial treatment of the film's more serious themes doesn't help the great cast. Fiennes and Tucci, in particular, deliver dialogue with athletic skill, but they and the rest of the cast are burdened with embodying stock characters who exist only through one or two salient features. Instead of reaching the awe-inspiring heights of their productions, the sophistication of the performances narrows down to monotony. ♦