On May 2nd 2011 Osama bin Laden, founder and leader of the Islamist militant group al-Qaeda and member of the FBI's ten most wanted, was killed by US Navy SEALs in Pakistan.

Although everyone knows how this particular US mission ended, little is known as to the nitty gritty, behind the scenes developments leading up to this event. Kathryn Bigelow's film, as it reveals from the start, is based on first hand accounts of actual events.

Two days after the atrocities of 9/11, President George W. Bush declared "The most important thing for us is to find Osama bin Laden. It is our number one priority and we will not rest until we find him".

Two years later and Maya (Jessica Chastain) is a fresh faced CIA agent who is given the impossible task of finding Osama bin Laden. It's a mission that sends her all around the world as she follows up various Intel, slowly piecing together a puzzle that will hopefully reveal the whereabouts of the FBI's most wanted criminal.

It's a mammoth task that can't be handled alone, which is why she has the help of other agents, including Dan (Jason Clarke), Jessica (Jennifer Ehle) and Jack (Harold Perrineau).

Years go by, as Maya plays the real life equivalent of 'Where's Wally?', until she finds a lead that could quite possibly lead to the home of bin Laden. Now all she has to do is convince her bosses, including the new president, that she really does know where he is.

Don't get me wrong, it's OK, but they've built like a Death Star out of Lego that quite frankly pisses all over your effort.

After impressing with her vampire feature Near Dark in 1987, Kathryn Bigelow's career was overshadowed somewhat by her marriage to fellow director James Cameron; this was probably also mainly due to the mediocre work she was directing at the time (Blue Steel, Point Break, K-19: The Widowmaker).

Then she hit gold – literally - in 2008 with The Hurt Locker, which won six Oscars including Best Film and Best Director. The film, about a three-man disposal team during the Iraq war, teamed her up with its writer Mark Boal, who was a journalist embedded with the US army in Iraq in 2004.

Obviously the pair hit it off as they reunited for Zero Dark Thirty, which although shares similar themes with their previous project, is a very different beast in its own right.

The biggest hurdle that clearly confronted Bigelow was how to present a feature where the ending is widely known to one and all on the planet. Her take on events was a smart one: to not focus on the result at all; instead relate the intriguing back story that leads to it.

This means that the film is not your average action flick. The vast majority of the film's almost three hour length is devoted to the one woman search team led by the character Maya. With Boal's intense and intriguing script as a guide, Bigelow creates a cinematic maze that doesn't rely on the film's exit strategy – because everyone knows how it ends – which allows her take her audience on the more curious journey there, with all its dead ends and false hopes with every twist and turn.

She also manages to do this with a character, who is less emotive and more of as conduit to the events that unfold. In that sense it's difficult to connect with Chastain's character on an emotional level, as she displays very little throughout. And yet Chastain is the only true constant, and acts as a superb guide for audiences to follow. The only down side of doing this is that the film does come across as one woman's quest to find bin Laden, and that all the glory should go to her. The reality however, is that it probably played out more as a team event, with more people possibly involved deeper than the film lets on. But in terms of the film, you're willing to give Bigelow the benefit of the doubt.

And considering how little action there is, Bigelow still manages to keep a high level of interest and suspense from beginning to end. Perhaps she's helped by the fact that these events are (presumably) real, which helps to sustain and hold interest throughout.

There's something refreshingly matter-of-fact about it too, with Bigelow thankfully giving a cold shoulder to a more gung-ho approach for the big screen. Much has been made about the torture scenes contained within, but they are by no means gratuitous; they merely reflect the kind of lengths gone too in order to gather sensitive information. Usually, in the real world, very little is given over with the use of 'pretty please?', and this film merely gives a more honest, albeit troubling, account of how Intel is recovered.

If you skip over the political issues and the moral ambiguities of it all, Bigelow has produced yet another masterful and assured piece of filmmaking.