“Zero Dark Thirty” follows the CIA’s manhunt for Osama Bin Laden. The film revolves around the sharp CIA agent Maya (Jessica Chastain), who spearheads the investigation. “Zero Dark Thirty” is a somber, intense and impressive film by Oscar-winning director Kathryn Bigelow (“The Hurt Locker”).

The film is effective in keeping the narrative grounded firmly in reality. It does a good job of portraying the difficulty and frustration of the Bin Laden search. Though the movie follows a linear narrative, the search for Bin Laden was certainly circuitous. As “Zero” shows, there was not one eureka moment, but a series of small steps forward with many steps backwards. While many films shy away from uncertainties to keep to a clear, clean narrative, “Zero” embraces them, the realism of the search strengthening the movie. Even as we get closer and closer to finding Bin Laden in the movie, we never get that it’s a sure thing.

There’s been quite a lot of controversy over various aspects of the torture scenes in the movie: that they weren’t accurate because the CIA didn’t use them to find Bin Laden, and that the movie promotes the use of torture to extract information. The scenes are intense and difficult to watch, but “Zero” doesn’t seem like the movie is promoting the use of torture to get information. Ultimately, it is unclear if the information the characters get from the interrogations is useful.

There’s a secondary storyline to the manhunt that doesn’t come through as well: the changing role of the CIA and how that has affected its priorities. We get hints of the theme from Maya’s bosses, but it’s mostly pushed to the side as the search progresses.

In terms of performances, “Zero” belongs to Jessica Chastain. As Maya, she finds her voice as the movie progresses. She transforms from the newest CIA agent in the Pakistan office who stands quietly in the interrogation room to the only person in a room full of CIA leaders who has complete conviction that they have found Osama Bin Laden. While we see Maya find her voice, the movie would have benefited from spending more time on how she formed her views. We see her looking conflicted during earlier interrogations, but the way her perspective on interrogations changes with time is not really shown.

Rounding out the rest of the cast, Jason Clarke and Jennifer Ehle play additional CIA agents, Kyle Chandler portrays Maya’s boss, and Chris Pratt (“Parks and Recreation”) stars as a Navy SEAL. I’m a big fan of “Parks and Recreation,” but it was a bit distracting to see Pratt in the movie. He provides some levity but doesn’t seem to quite fit the tone of the rest of the movie.

“Zero Dark Thirty” is a somber portrayal of a manhunt. It is intense, draining and completely worth seeing.