Directed by Joe Wright. Starring Saoirse Ronan, Eric Bana, Cate Blanchett, Tom Hollander, Olivia Williams, Jason Flemyng 15A cert, gen release, 111 min

Hit girl Saoirse Ronan kicks middle-brow ass in this high-grade hokum from oh-so-tasteful Joe Wright, writes DONALD CLARKE

YOU DO worry a little when a middle-brow director sets out to tackle genre entertainment. Too often the result turns out to be unsatisfactory as matinee entertainment and underwhelming in its efforts to spread a little “class” about the place.

And you don’t get much more middle-brow than young Joe Wright. Nobody is likely to confuse Atonement, Pride & Prejudiceor The Soloistwith Attack of the Swamp People.Still, he’s entitled to have his bit of fun, and Hanna– an entry in the sparse killer-teenager genre – certainly moves him away from the bone china and blandly inspirational denouements.

As compromised efforts go, Hannais not at all bad. There are at least three chase sequences worth staying awake to enjoy; the Chemical Brothers soundtrack throbs and pulses with satisfactory menace; and, though it’s rare to hear so many good actors deliver so many bad accents, the top-notch cast throws itself into the action with considerable conviction. Still, it’s hard to escape the sense that the director feels the material is a little bit beneath him.

We begin in some part of the Arctic tundra, with the titular youth pitting herself against an unlucky and doomed reindeer. Puzzlement abounds (in theory) as we travel back to the cabin where Hanna lives with her rugged, bearded father.

If you’ve seen the side of a bus in the past month, you will know that Saoirse Ronan, star of Wright’s Atonement, plays the odd, largely humourless adolescent. Rebounding from the embarrassment of the wretched The Lovely Bones– in which, to be fair, Ronan acquitted herself admirably – the youngster makes an excellent (ahem) fist of her first action role.

The faintly spooky, old-before-her-time quality that hangs around Ronan is ideally suited to playing a home-schooled semi-hermit encouraged to eliminate enemies with one jagged blow. Not all the fight scenes, often edited in suspiciously brief shots, are convincing, but the solidity of her performance helps distract from the technical inadequacies.

Anyway, back to the heap of absurdities that passes for a story. It soon becomes clear that Hanna’s dad (Eric Bana as an unconvincing German) was once some sort of clandestine operative, and that he has a long-standing beef with a top female spook (Cate Blanchett as an unconvincing Dixie spinster) whose obsessive nature is demonstrated by a need to clean her teeth so vigorously that gums bleed.

When Hanna feels herself ready for conflict, she will activate a puzzling device that (I honestly can’t be much more helpful here) will trigger the beginning of the film’s second act. The button is pressed. Espionage-ready Blanchett DuBois springs into action and, before you can catch a breath, Hanna is imprisoned in a tasteful, minimalist cell.

Something then happens that it would be unfair to reveal and, after shooting those guards she hasn’t kicked in the head, our heroine, sprung in a desolate part of north Africa, sets out to evade the sinister representatives of western tyranny.

The film’s main body alternates between a class of (largely successful) dime-store hooey and the expected (mostly boring) gestures toward art-house respectability. When Tom Hollander, playing a camp assassin, is on screen, Hannacrackles with vulgar energy. When Wright indulges in his prettified showboating – artfully fuzzy shots of Ronan taken at a drunken angle – weak-bladdered viewers could be forgiven for lunging towards the lavatory. The film’s most indulgent moment finds Wright shooting an irrelevant flamenco dance sequence in its long, pointless entirety.

All these whinges noted, it must be acknowledged that the heart-racing sequences outnumber the tedious ones by a satisfactory margin. It could have been much worse, Joe. Now back you go to that Henry James adaptation.