Film: Without a trace

In the film yhe main character is a young give who suffered a seizure the kidnapper was still alive and he watched her everyday. She went to the police so many times but they didn't believe in her story. One day the kidnapper came to their house but she wasn't there he kidnapper her sister.
The police still didn't believe her story, so she decided to solve  their problem on her own. She can contact with the kidnapper and she followed his instructions, until the middle of the forest when she arrived to the right place she had to fight with him. Finally she killed him.
Her sister can escape and a few minutes later arrived the police. When the police asked her fer the kidnapper she said: "Who?"
I like a lot this film, I like the intrigue generated by the plot. The film have a very good actors and I think that the end is amazing, very inexpected and fantastic. I really like this film.