ROSEWATER Nice close-up of that wall, Scorsese.

LONGTIME VIEWERS of The Daily Show will recognize former Newsweek reporter Maziar Bahari as a frequent guest on the program. In 2009, he appeared in a segment that also featured Daily Show contributor Jason Jones pretending to be a spy. It was meant as a joke, but it led, in part, to Bahari's incarceration. The Daily Show's host, Jon Stewart, felt kind of bad about it. So he took a summer off from the show and directed a movie about Bahari, writing the script with J.J. Abrams and casting Gael García Bernal as the Iranian Canadian journalist.

At the time of the Jones/Bahari interview, Bahari was in Tehran reporting on Iran's 2009 presidential election and its subsequent fallout. Dictator Mahmoud Ahmadinejad had, supposedly, roundly trounced his challenger, Mir Hussein Moussavi (along with two other candidates on the ballot), but the margin of his victory upended expectations and invoked protests of fraud among the Iranian citizenry. In the confusion, Ahmadinejad's regime rounded up dissidents—including Bahari, whom they considered a revolutionary. He was held under charges of espionage and spent 118 days in an Iranian prison, either in solitary confinement or undergoing moderate torture at the hands of a "specialist"; Bahari eventually made a televised confession under duress before he was freed due to pressure from the international community.

It's not the type of story you'd expect from the star of Half Baked and Big Daddy. But Stewart's humor has evolved over the 15 years he's hosted The Daily Show. He isn't a comedian anymore, he's a cultural critic—a critic of the American news media, in particular—who is deeply, almost inextricably embedded in the field he surveys. It's a conflict-riddled perch, and Stewart typically deflects accusations of having it both ways by asserting his ground as a comedian and satirist. However disingenuous this might be, Stewart's instincts are otherwise pretty sound: He habitually speaks out against hypocrisy and injustice with intelligence and wit.

Which makes Rosewater's straightforward sentimentality a little surprising. The script is a scrum of alternately somber and playful moments, and the mixture generally works, with a few awkward elbows. Stewart's repeated jabs at his home state of New Jersey are pretty funny, and the characterizations of both Bahari's driver (Dimitri Leonidas) and his interrogator (Kim Bodnia) are thoughtful and nuanced. The movie's biggest problem comes when Bahari's meant to be alone in his cell. His father and sister—both dead—appear onscreen as full-fledged characters, voicing his inner monologue and adding a few chin-up inspirational quips.

But whatever greenness Stewart displays as a filmmaker—at one point there's a graphic of a word cloud that interrupts the narrative and will pull you right out of the movie—is offset by his earnestness in telling Bahari's story. The opening stretches, detailing the election and the underworld of Moussavi's supporters, are excellent, rumbling with a palpable sense of what the energy must have been like in Tehran during the election. And again, the character of Bahari's unnamed interrogator/torturer is exceptionally drawn: Instead of an inhuman monster, the film depicts a fearful man repressed by his religion and his job. If the overall picture drawn by Rosewater is slightly glib and predictable, these details indicate that Stewart has a real gift for storytelling. He won't be able to conveniently retreat back to the role of a comedian after this.