"Hanna" is a tense spy thriller about a young girl who is a trained assassin who has kept herself hidden from the outside world. The man who was training her from a very young age is an Ex C.I.A. operative who is in hiding in Finland. One day, the girl is deemed ready for her first mission in Germany, also to reunite with her father. The journey was long through the hot Anatolian highlands of Turkey to the city of Berlin in Germany.
Meanwhile, when the chief intelligence officer gets wind of the girl being alive after nearly 16 years, she must act fast to take her down. She discovers the girl traveling north from Turkey along with a British couple. The girl soon realizes that she was part of a clandestine genetics project funded by the C.I.A. to create super soldiers that have suppressed emotions and empathy. To do this pregnant women were recruited from abortion clinics all over Europe to find healthy test subjects. Out of all of the pregnant women who were part of this secret research project, only the girl's mother escaped with the help of an operative. Fearing that news of the project would leak, Langley ordered the termination of the project and any test subjects that might have escaped. This coincides with a rigged car accident where the girl's mother is shot in the passenger seat.
When the girl arrives in Berlin, she begins to discover parts of her past and what she must do to survive. In a final conflict with the intelligence officer who has tried to kill the girl only to be wounded. The final climax is where the officer is shot through the heart killing her instantly.
Free from any retribution from the C.I.A., Hanna returns to her solitary life in the wilds of Finland's Arctic region hunting reindeer. The film does a full circle effect using the plot line of hunting in the beginning and ending.