Mikael Blomkvist (Michael Nyqvist) and his colleagues at the magazine Millennium are preparing a special issue of their magazine dealing with trafficking in Sweden, in which several prominent members of society will be revealed to have taken advantage of young girls. At the same time Lisbeth Salander (Noomi Rapace) returns to Sweden after a lengthy stay abroad, only to find herself in the middle of a conspiracy and the suspect in a murder of one of the Millennium journalists. As the story progresses Mikael realizes that his trafficking story and Lisbeth’s troubles are somehow connected, and the two of them, each in their own way and separately from each other, decide to get to the bottom of everything.