Since 1982, Kathryn Bigelow has amassed, upon reflection, one of the more intriguing resumes of the past thirty years. Until this year, in a decidedly mercurial body of work, she had directed seven distinct movies which followed no formula and were beholden to no genre; there is a discernible sense that she thrives on never repeating herself. She directed Willem Dafoe that year in his first credited film role in “The Loveless,” an homage to “The Wild One.” Five years later, she created the 1987 vampire flick “Near Dark,” a movie whose reputation only grows with time. At the end of the ‘80s, she filmed the Jamie Lee Curtis cop thriller “Blue Steel,” and followed it with 1991’s quotable cult classic, “Point Break,” and a personal late-night cable favorite, 1995’s Ralph Fiennes-Angela Bassett noir, “Strange Days.” In 2000, Sean Penn starred in the poorly received “The Weight of Water,” while in 2002, she made “K-19: The Widowmaker,” a critically well-regarded Harrison Ford flick set on a Soviet submarine which snared a mere 35 million dollars at the box office. Seven films over 20 years and each marked with an asterisk, most described with the caveat of guilty pleasure. In the summer of 2007, Bigelow transported an estimable crew and a cast of relative unknowns to Amman, Jordan, and, for the reported pittance of 11 million dollars, filmed her eighth feature-length film, “The Hurt Locker,” which chronicles the final month of deployment in Iraq for a U.S. Army bomb squad in 2004. For this film, no qualifier is necessary: “The Hurt Locker” is an unequivocally tremendous and authoritative achievement. It is the seminal work of her career.

Girded by seven painstaking sequences with each focusing vividly on a day in the field, “The Hurt Locker” is a film set during wartime but not reliant on action scenes blazing; it’s not classically heroic either. Raw, real, and suffocating, the seven lengthy and deliberate scenes are brilliantly executed gripping pillars of a movie entrenched in the working lives of soldiers who attempt to disarm bombs and improvised explosive devices. Bigelow sets this intensive, concentrated tone from the first moments of the film in a powerful opening chapter. Sergeant Matt Thompson (the chameleonic Guy Pearce) ploddingly walks in his protective suit like a moon-landed Apollo astronaut toward a bomb nestled in a deserted Baghdad street. Keeping watch with eyes darting from doorways to rooftops are the sensible Sergeant JT Sanborn (the dependably strong Anthony Mackie of “Half Nelson”) and the emotionally susceptible Specialist Owen Eldridge (an effective Brian Geraghty). The scene unfolds methodically, like the deep inhales and exhales from inside Thompson’s mask, and the stillness is disquieting and deceptive.

With 38 days left in their rotation, the explosive ordinance disposal team is joined by a new leader, Staff Sergeant William James (a swaggering Jeremy Renner), a brash veteran of 837 bomb detonations who is equally reckless and fastidious. Relatively young despite his experience, James is a hot-wired, fractious presence. (He cranks up Ministry to unwind.) There’s a healthy element of a character study in the script by Mark Boal, (who also penned the story which became the movie, “In the Valley of Elah,”), and the film delves into how the disparate personalities of the team coalesce, but, basically, it’s a story of daily vulnerability as the trio sets out alone in their armored vehicle to defuse the innumerable IEDs. Ever-present danger is the normality. Robots fixed with cameras glide around the bombs, but the devices require a human touch to silence them. In one instance, the team must decipher a pentagon of serpentine wires running from an IED dug into the city street to an apartment building; on another assignment, as circumspect stares bear down from urban rooftops, Sanborn and Eldridge, with guns drawn, scan for snipers as James attempts to dismantle a bomb lodged intricately inside a car. The camera work in these scenes by cinematographer Barry Ackroyd is superb. Ackroyd has filmed the vast majority of Ken Loach’s canon as well as Paul Greengrass’ “United 93,” and he excels at capturing images with a claustrophobic lens. From Glaswegian alleyways to London bed-sits or the cabin of a Boeing 757, and, now, a decimated Iraq, his camera provides a stark, palatable, unnerving intimacy. Ackroyd’s camera has never been afraid to expose the wrenching quotidian; “The Hurt Locker” doesn’t shy away either.

The film leaves Baghdad for an assignment in the desert where the team comes to the unintended assistance of a band of hired civilians led by “Contractor Team Leader” (a ruddy Ralph Fiennes). A firefight erupts. Amongst the mayhem, the scene illustrates jarringly beautiful cinematic shots of empty cartridges bouncing off the ground, and a fly daintily resting on an eyelash. The lengthy battle-field engagement highlights the judicious work of editors Bob Murawski, a veteran of Sam Raimi’s films, and Chris Innis, who expertly mesh the violence into the agonizingly protracted stand-off.

A tangential scene in which a vengeful Staff Sergeant James sneaks off the base for a planned act of retribution is the only hurried sequence in the film, and, consequently, the weakest. It’s unconvincing because it’s too quick and too brusque; the other emotionally charged moments develop and envelop with patient buildup, but this scene just flashes by. It also illustrates a flaw in the balance of the characters. While “The Hurt Locker” follows the three soldiers, the film tips its interest too heavily to the plight of Sergeant James. The movie shows scenes of his home life, and his paternal interaction with a cheeky, football-playing Iraqi kid who calls himself Beckham. It’s useful to the character’s edification but the two other team members could have profited from the same level of contextual perspective. The vulnerable Eldridge is fleshed out in a few illuminating scenes with an Army psychiatrist, Colonel John Cambridge (Christian Camargo), but very little is unearthed about his background. And Sanborn is underwritten, with bits of his life tossed out almost as asides. Especially when portrayed by an actor as stout as Mackie, who will become a more heralded movie presence in the next few years, it should be considered a missed opportunity.

But the final major sequence in Baghdad underscores the tenacious filmmaking exerted by Bigelow. An Iraqi man, an innocent pawn, with a time bomb clamped to his torso by a metal vest of chain and locks like an illusionist’s final harrowing escape, stands pleading in a vacant square. The team arrives at the military checkpoint and the emotion of the scene escalates as the helplessness the man and the American soldiers feel turns to anguish. Bigelow remains unrelenting to the end, with no respite from the tension, and no conclusion to a story where, in 2004, a soldier re-upped for war and misery in perpetuity.