In Goya's Ghosts, the maverick filmmaker Milos Forman has accomplished the unimaginable: He has somehow wrested a good performance from Natalie Portman. As Inés Bilbatúa, a wrongly jailed woman who becomes politically inconvenient upon her release, Portman eschews the pipsqueak shrillness that made her so maddening in Closer and Garden State. She immerses herself in the character's unglamorous fate, devolving from a happy-go-lucky blonde in white lace (we first see Inés as she poses in Goya's studio) to a mentally disturbed, prematurely old vagabond whose teeth, hair and skin have turned frighteningly ashen.

The movie begins in 1790s Madrid, where black-robed clerics at the Holy Office of the Inquisition denounce Francisco de Goya's etchings (grim fantasies that reflect the injustices of the day) as "demonic filth." One inquisitor, on learning that Goya's prints are sold in Rome and elsewhere abroad, wails: "This is how the world sees us!" Forman seats these holier-than-thou hysterics at a long rectangular table in high-backed chairs—the joke being that the Inquisition could be a corporate boardroom at any place and time in history, with Catholics as stand-ins for businesspeople who don't "get" art or its significance, despite Goya's status as court painter to the King of Spain. Alone among the priests, Father Lorenzo (Javier Bardem) defends the artist's work as showing "the true face of our world."

The first few instances I heard Lorenzo speak, I couldn't figure out what Bardem was going for in his lazy, slurry speech rhythms; the actor sounds as if he's trying to scale an octave too high for his range, while the words dawdle. Yet the boldness of Bardem's conception grew on me, especially in a dinner-party sequence in which Goya (Stellan Skarsgård, who portrays a dynamic individual, as opposed to a biopic stiff), Lorenzo and Inés' distraught parents talk about Inquisition detainees who are "put to the question," a euphemism for sanctioned torture. The guests, believing that this primitive technique had been discarded, are unnerved by Lorenzo's gleeful exclamation "The church is bringin' it back!" (That dropped "g" is a masterstroke.) "The fear of God," the priest assures them, "will prevent you from making a false confession." José Luis Gómez, splendid as the wealthy Signor Bilbatúa, dissents from the holy man's certainty with exactly the right mix of gallantry and outrage.

Forman was astute to cast Portman as a torture victim. Her little-girl fragility and small-throated voice contrast so horrifyingly to the vicious treatment she receives that it's as if a member of our own family is under attack. Which in a sense holds true: Forman's mother was abducted by authorities in the 1940s—she perished at Auschwitz. Goya's Ghosts gains its gravitas partially from that, but also in the moviemaker's grasp of warfare's eternal repeats. Battle dates change; misguided rationales and devastating effects don't. When the scene shifts to the Napoleonic chaos of 1807, invading French soldiers abolishing the Inquisition leave streets and fields strewn with dead civilians. A montage of gory killings accompanies Skarsgård's off-camera remark, "Liberty, equality, and brotherhood." It's an audacious visual reminder of what governments do in the name of those ideals—and what those ideals, then as now, are touted to cover.

Goya's Ghosts

is rated R. It opens Friday, Aug. 3, at Fox Tower.