Saoirse Ronan has built herself quite a diverse career and she’s still a couple of years shy of 20. She’s done comedy with Michelle Pfeiffer in Amy Heckerling’s never released in the theatres terrific I Could Never Be Your Woman (on Netflix); drama in Atonement for which was nominated for an Oscar, more drama in The Lovely Bones, and now she stars as a girl literally fighting for her life in Hanna.

Hanna has been living of the radar in the middle of the frozen tundra with her father Erik played Eric Bana. He is a former spook who went underground to save Hanna and he has trained her to protect herself from everyone and everything. She has spent all her life isolated memorizing facts about the world and life because she has never met another person and her life is somehow in danger from Marissa Weigler a CIA agent played by Cate Blanchett. You don’t exactly know why Hanna is a target but the only way that Hanna can survive — and try to live as normal as possible — is to outlast all the people who want her dead. She was trained very well by her dad. She’s stealth, kills without thought or emotion and is determined to try and figure out how to have a life without living in hiding. But she is not prepared for human interactions and she learns a lot about being a girl and family from a kooky and loving British family on holiday led by Olivia Williams that she meets up with on her travels.

Hanna benefits from not being the first film where a teenage girl kicks ass — remember Hit Girl in Kick Ass? This doesn’t push any buttons like that film did maybe because it’s not a film about revenge but about survival (and it helps that she doesn’t wear a costume and call people the c-word.). What’s good about the film is that you don’t for one second not believe that this girl could kick your butt up and down the street. That’s progress in my book.