'Hanna' is a teenage killing machine

With bone-crunching action, snazzy direction by Joe Wright and a whomping electronic score by The Chemical Brothers, the espionage-thriller "Hanna" grabs you by the neck and never lets go until the closing credits.

Only then will it hit you: The previous two hours haven't made a lick of sense.

That's acceptable if you're willing to live in the moment. "Hanna" is full of thrilling sequences, exotic locales and delicious villains, particularly Cate Blanchett as Marissa Wiegler, an amoral CIA honcho whose syrupy Southern accent and fluent German are equally chilling. Saoirse Ronan (who starred in Wright's very different "Atonement") plays the title character, but Blanchett is the one who will put a smile on your face.

The story begins somewhere in the Arctic Circle, where rogue agent Erik Heller (Eric Bana) has been shaping 16-year-old Hanna into a ruthless, sleepless killing machine. "Papa, I'm ready!" she says, after nearly snapping his neck. Her assignment: Infiltrate a CIA compound in Morocco and kill Wiegler. Meantime, Heller must get to Germany. He swims there.

What follows is a fast-moving game of cat-and-highly-skilled-mouse, though things really kick into gear when Wiegler teams up with a paunchy, sexually ambiguous assassin named Isaacs (Tom Hollander), who is almost as much fun as she is. As for Hanna, when she's not breaking elbows and gouging eyes she's trying to decipher the unusual DNA code in her medical file.

Some questions: Do Hanna and Wiegler share a deeper connection? What is Wiegler's real history with Heller? And did Heller really just trek across Finland -- in a business suit? "Hanna" is fun while it lasts, but not a minute longer.