Crusading publisher Mikael Blomkvist has decided to run an explosive expose of a wide-ranging sex trafficking operation. Just before the piece is published, the two reporters responsible are murdered. The fingerprints on the murder weapon belong to his friend, the troubled hacker genius Lisbeth Salander. Blomkvist, convinced of Salander's innocence, plunges into an investigation. Meanwhile, Lisbeth herself is drawn into a murderous game of cat and mouse, and is forced her to face her dark past.