By Chris Nashawaty
Updated August 25, 2011 at 04:00 AM EDT
Jasin Boland

After her Oscar-nominated breakout performance in 2007’s Atonement, Saoirse Ronan became someone to keep an eye on. At 13, the Irish ingenue with the alabaster skin and otherworldly blue eyes was so self-assured on screen, she seemed like one of those rare child actors who come along once a decade or so. The only question was, would her career lift off like Jodie Foster’s or flame out like Lindsay Lohan’s? The verdict was put on hold with 2009’s The Lovely Bones — a dreadful adaptation in which she was one of the few bright spots — but Hanna (2011, PG-13, 1 hr., 51 mins.) delivers it loud and clear: She’s here to stay. Reteaming with Atonement director Joe Wright, Ronan plays a shy, quiet teenager who lives in the snowy hinterlands of Finland, where she’s been trained by her ex-CIA-operative father (Eric Bana) to fight and kill. She may look like sugar and spice, but she’s a natural-born badass. In the doozy of an opening scene, Hanna wounds a reindeer with an arrow, then, just as you think she’s about to show remorse, she whips out a gun and finishes the job with a kill shot to the head. Who is this girl? The movie wisely waits to answer that. In the meantime, Hanna ventures out into the world, which makes her father’s former CIA handler (a deliciously sinister Cate Blanchett) twitchy. Hanna is a loose end — one with a knack for snapping the neck of every goon sent to get her. I’ll admit that the idea of Jason Bourne in the body of a teenage girl sounds ridiculous. But Ronan shows us the confused kid beneath the icy killer’s exterior. I can’t wait to see what she does next. B+