Why would the director of an impeccably polished period tragedy like Atonement choose to make an action movie? Well, why not? And if Hanna’s anything to go by, it’d be no crime against cinema for Joe Wright to spend the rest of his career crafting action movies. In fact, many might demand it of him.

Not that Hanna is just any old action picture. Brit director Wright takes what could easily have been a by rote, gunfire-stacked Hit Girl-like cash-in and executes the material with the same devil-in-the-details approach that made Atonement so wrenching. Wright isn’t just concerned with making a ball-cracking actioner (though he definitely succeeds there); he puts value in a surfeit of old school moviemaking rules that few take the time to acknowledge nowadays.

For example, the slow burn. When we’re introduced to Hanna (Saoirse Ronan), she’s clad in animal furs, hunting a reindeer in a desolate, frost-bitten landscape. In a seamless blend of style and substance, she’s treated to a fantastic title card moment of pure iconic clout – before Wright winds things down so we can get to know our strange little heroine.

She’s 16, we learn, and living in the wilds of Finland with her ex-CIA father Erik (Eric Bana). He’s trained her from birth to be strong, resourceful, smart. And when he feels that she’s ready, Erik will let her flip a switch that will alert their whereabouts to his ex-colleague Marissa Wiegler (Cate Blanchett). Armed with that knowledge, Marissa will make it her mission to kill both Hanna and her father.

Ghostly and attentive, Hanna makes for a bewitchingly unconventional lead. Perfectly captured by Ronan (who worked with Wright on Atonement), she presents Hanna as a fascinating enigma; quirky and serious and one heck of a grappler. The joy and humanity in Wright’s film comes from seeing Hanna unceremoniously exposed to the outside world, adrift from everything she’s ever known, then watching as her cheeks gradually fill with the colour of life.

Though continually turning tricks, blending sly storytelling with some remarkable set pieces, Wright never lets things get too bogged down in plot. While the Bourne films are an intricate labyrinth of false turns and laundered lies (and that’s how we like them), Wright and screenwriters David Farr and Seth Lochlead keep Hanna simple. They understand that Hanna’s journey – both internally and externally – is the real story, not the MacGuffin of her origins or her supposed purpose in a CIA game plan (which any comic book fan could easily predict).

Further polishing Hanna is a killer soundtrack courtesy of the Chemical Brothers. In an era when movie scores are gaining much renewed acclaim thanks to big name authorship (Trent Reznor with The Social Network, Daft Punk and, uh, Tron: Legacy), the Chemical Brothers don’t miss a beat in their hollering, atmospheric soundscapes, adding heft and wallop to Wright’s already-stellar moving images.

Talking of images, Hanna’s packed with bold visual design. Blanchett, on fantastic form as the drawling Texan CIA agent, appears in Hanna’s most brilliantly orchestrated shot, emerging from the shadows inside the gaping, razor-fanged maw of a giant funhouse wolf. Meanwhile, Bana gets his own iconic moment in the form of an underground skirmish, while he convinces as an attentive father at the film’s opening.

Where Hanna stumbles is in its final act. As it seeks to find a satisfactory conclusion, it suddenly realises that its lightweight plotting hasn’t really set itself up for one. There’s no massively devastatingly twist (though there is a twist, to be sure), so instead we’re subjected to scene after scene of running and yelling, as confrontations turn into chases that lead to further confrontations and chases. Meanwhile, the film’s final line, while clearly linking up to its opening scene, feels horribly overcooked.

If Hanna succeeds in anything above all else, it’s in further establishing Saoirse Ronan as a young actress going places. Adeptly navigating both Hanna’s emotional and physical currents, she blows this starmaker of a role out of the water. Here, also, is proof that Wright can handle more than sumptuous costume dramas – his first foray into full-blown action territory results in a pacy, stylish revenge thriller. 4/5