Kathryn Bigelow's slow-burning and brilliant Zero Dark Thirty presents itself as "based on firsthand accounts of actual events." And while some people - U.S. senators, the acting head of the CIA among them - have challenged its veracity on certain key points, this much can be said: As a hugely compressed account of the Osama bin Laden manhunt, as a compelling but troubling look at "black ops" tradecraft, and as a riveting portrait of a fiercely determined woman working in a male-dominated sphere, the film is a resounding success.

Yes, we know the outcome: bin Laden shot dead by Navy SEALs in his compound in Bilal, Abbottabad, Pakistan, on May 2, 2011. And still, every step leading to that nighttime raid - and every step the SEALs take moving stealthily up the narrow stairs of bin Laden's house - is fraught with tension and dread. Bigelow - in tandem with screenwriter Mark Boal, her partner on their Oscar-winning The Hurt Locker - is simply at the top of her game.

And so is Jessica Chastain. The actress, who seemed to be in every other movie released in 2011 (landing a supporting-actress Oscar nomination for The Help, winning heaps o' praise for her work in Take Shelter and The Tree of Life), stars as Maya, a CIA officer obsessed with tracking down the mastermind behind the 9/11 attacks. Based on a real operative in the agency, Chastain's Maya is cool and composed, her eyes often hidden behind aviator glasses, her expression unrevealing. Maybe there's a twitch of discomfort as she observes a colleague (Jason Clarke) brutally interrogating a suspected al-Qaeda contact, or maybe that was just a fly buzzing annoyingly around her in the hot, dirty cell.

If Zero Dark Thirty (the title is military-speak for half-past midnight) represents the globe-spanning, 10-year search for bin Laden - full of false leads and fatal attacks - it also represents the personal journey of a woman who has nothing else but this mission. Over dinner at the Islamabad Marriott, a fellow agent, another woman (a terrific Jennifer Ehle), asks Maya if there's a man in her life. There isn't.

And after a meeting at a CIA "black site" goes terribly wrong and Maya is forced to return Stateside, to continue her quest on laptops and satellite monitors, she tells her boss: "A lot of my friends have died trying to do this. I believe I was spared so I can finish the job."

Her tone isn't self-righteous, or messianic. But maybe it is a little crazy. Does Maya have anything else to live for?

Agents and embassy officials, special operations commandos and Saudi informants, White House aides and al-Qaeda detainees - they come and go, and Maya takes what information she can, and gives back what she must. What is remarkable about Chastain's performance is that we can see the human being behind the computerlike efficiency.

Bigelow has to be one of the best action directors working today (revisit her over-the-top surf movie/heist pic Point Break), and when Zero Dark Thirty goes from intel procedural into attack mode (literally - the two Black Hawk helicopters whirring across the Afghan mountains to descend on their target) it does so with heart-stopping suspense. A monumental achievement that documents a coordinated and complicated response to a monumental tragedy, Bigelow's film leaves us with a question that resonates long into the night.

Climbing aboard a huge military cargo jet for the trip home after identifying bin Laden's corpse, Maya is greeted by one of the crew.

"You must be pretty important," he says. "You've got the whole plane to yourself. Where do you want to go?"

Where, indeed.


Contact Steven Rea at 215-854-5629 or srea@phillynews.com. Read his blog, "On Movies Online," at www.philly.com/onmovies.