In espionage, how does one reconcile a lead driven more by hope than knowledge? How can you determine the almost incalculable risk of inaction? And should you act, where might that take you? Nowhere? Into a fatal trap? Or, as we find at the exhaustive end of Zero Dark Thirty, to an empty uncertainty that follows the death of the quarry?

Director Kathryn Bigelow and screenwriter Mark Boal’s follow-up to The Hurt Locker is simultaneously a long-form journalism piece, docudrama, thriller, action film and character study. And the fate of the prey is hardly a spoiler when his name is Osama bin Laden, whose pursuit over a decade-long, post-9/11 manhunt is rigorously dissected here.

Procedural enough to be broken into chapters, Zero is never a dry, dispassionate presentation of exhibits and evidence. And while its conclusive Navy SEAL raid is depicted with the bracing, muscle-knotting intensity that’s Bigelow’s stock-in-trade, it’s weary and wise enough to avoid the obvious ooh-rah. Its unshakably monolithic power and suspense derives not from bullets fired but dominoes felled to arrive at that moment.

“Everyone breaks, bro. It’s biology.” Such is the deceptively dulcet tone of Dan (a mesmerizing Jason Clarke), a CIA interrogator at an off-book “black” site in Pakistan. It’s there that the audience, along with newly arrived CIA agent Maya (Jessica Chastain), is disturbingly oriented into his day-to-day work.

Although limited to the first act, Bigelow’s depiction of waterboarding, sensory abuse, stress positioning and humiliating nudity is astoundingly difficult to watch — as it should be. The movie neither condones nor condemns. It simply presents the circumstances and allows viewers to arrive at unguided judgment — less about its efficacy in eliciting information than whether it was worth the moral quagmire.

Such ruminations are but one nuance of Zero that draw the most magnetic performance yet out of Chastain, a chameleonic character actress given the lead here. It’s work that simmers rather than explodes, all the trickier a balancing act for it and resolutely compelling throughout.

Maya is very much aware she is “the other” — a woman in a field dominated by testosterone and machismo. It’s not an ego-feeding metaphor for Bigelow as the rare female action filmmaker. It’s a quietly motivational character trait, subtly underscored in Boal’s script and Bigelow’s staging — how Maya is shoved into the corner of a conference room at a pivotal point in her investigation or how she’s dismissively identified in a moment of accomplishment for which she’s yearned.

Zero’s critical detractors have pegged Dan and Maya as detached ciphers — icy and impenetrable pawns whom Boal and Bigelow strategically move for the sake of their narrative endgame. A counterargument: When eagerness is the deadliest emotional investment someone can make, isolative tendencies become a shield.

As Maya and Dan seethe, so does the film. Catharsis is infrequent. Victories are few. The clash between statistics and instincts yields casualties. And heart, as often defined by Hollywood, here becomes just a physiological midpoint between brain and gut — trusted at the risk of peril. In some ways, this rough beast is the anti-Argo, an exceedingly entertaining film that cut its tension with satire and melodrama. Here, the human elements are simply rubbed so raw it takes some work to identify them.

Our journey into a heart of darkness to demand justice for thousands of lives may have been necessary. But Zero Dark Thirty understands it will never truly be done and still carries a weight and burden long beyond the moment of one man’s death. It’s one of 2012’s greatest films.

What Zero Dark Thirty isn’t, at least in terms of copious special features, is one of 2013’s best Blu-ray releases. Both that version and the DVD contain only four dinky featurettes, totaling less than a half-hour of footage.

No Small Feat is a boilerplate press-kit sneak peek. The Compound focuses in on the reenactment of the Abbottabad, Pakistan, raid, while Geared Up examines the authenticity of the Navy SEAL behavior. Lastly, Targeting Jessica Chastain takes a closer look at the Oscar-nominated lead actress’s characterization of Maya.

If ever a film cried out for comprehensive behind-the-scenes components, it’s this one. Perhaps now that the Senate Intelligence Committee has aborted its investigation into whether Boal and Bigelow received inappropriate access to classified information — coincidentally timed with the film’s virtual Oscar shutout — a more extensive home-theater edition is in the works.