To say that our gal Saoirse Ronan is impossible to typecast is something of an understatement. At the age of 17, the Carlow actress has already amassed an impressive body of work but there's not an obvious unifying thread among her films - unless that thread is a desire not to take on conventional roles. We first noticed her star quality in 'Atonement' (2007), when the then 13-year-old stole the movie (and the Oscar nod) from under the noses of more celebrated actors such as Keira Knightley and James McAvoy. That moving drama was directed by Joe Wright and the young English director has reunited with his young star for 'Hanna', an original drama about a young girl raised in isolation by her ex-CIA father (Eric Bana).

'Hanna' opens in a Finnish forest in which Ronan's character and her father share a hut and a penchant for sleeping with one eye open. It's clear that he has been honing her survival skills (she's particularly deadly with a bow and arrow) all of her young life, but it's equally apparent that his young charge is now ready for her mission: the elimination of a ruthless intelligence agent played by steely-eyed and sharply stilettoed Cate Blanchett.

'Hanna' is a film whose success entirely depends upon the slender shoulders of Ms Ronan, and she carries it with aplomb. "Saoirse is very young," says the director of his leading lady, ''but she's preternaturally talented.'' Indeed Wright is so confident of that talent that he's not afraid to include a number of extreme close-ups that make maximum use of his young leading lady's intense blue/green eyes.

Famously a fan of high-octane French movies, Wright's movie is replete with echoes of Beineix ('Diva') and Besson ('Leon', obviously). Indeed, as you watch one quirkily composed scene after another (complete with a pounding Chemical Brothers soundtrack), it's hard to believe that this is the same man who directed 'Pride and Prejudice'.

In addition to the excellent Ronan, who does a tremendous job in portraying both sides of this girl's character - the well-honed assassin and the naive youngster unused to what the real world has to offer - 'Hanna' features strong performances from Bana, Blanchett and Tom Hollander as a nattily dressed hit man. Though it's fact-paced and occasionally violent, the director lightens the mood by having our young heroine team up with a holidaying English family that includes Olivia Williams, Jason Flemyng and Jessica Barden, a young girl whose teenage obsessions (boys, celebs) are at complete odds with the life experiences of her new best friend.

Something else that sets 'Hanna' apart from standard hi-tech assassin thrillers is the balance the film maintains between the real and the fairy-tale (in this regard, Blanchett is very much the evil stepmother of the piece). Both come together neatly in the movie's denouément at Grimm's House in Berlin.

Though it will inevitably invite comparisons with the likes of 'Leon' and 'Kick-Ass', there's something about 'Hanna' that really makes it stand out. And that something is Saoirse Ronan.

Michael Doherty