Blomkvist and Salander rush back to Stockholm so he can access her Wennerstrom files. After reading over the files for three days, Blomkvist is dizzy with the possibilities, realizing that Wennerstrom has created an intricate business in which dozens of companies all own part of each other. He asks Salander how she acquired this information. Salander explains the electric cuff she bought from Plague many months ago. She states that she made a copy of Wennerstrom's hard drive. At a certain point, the computer program replaces the hard drive on Wennerstrom's actual computer so that any time he's using his computer he's really using the copy Salander has placed on an anonymous server.
After four days in Stockholm, Blomkvist receives a call from Malm, who says Dahlmann has been spotted at a bar with a Wennerstrom employee. Blomkvist, with Salander's help, breaks into Dahlmann's computer at work and discovers that he has been leaking Millennium information ever since he started working. Instead of firing him, however, Blomkvist calls a secret meeting of his trusted staff and tells them to spread the rumor that Millennium is falling apart so that Dahlmann can feed that information to Wennerstrom. Then, when Blomkvist has written his big Wennerstrom story, the news will be even more of a sensation. The staff happily agrees. Finally, Blomkvist asks Malm to give the news to Berger since she's still out of town. Blomkvist realizes he is making this request of Malm because he's avoiding Berger and her questions about what happened in Hedestad.
Next, Blomkvist packs up and travels to his cabin on Sandhamn to begin writing about Wennerstrom. During the course of his stay there, he exchanges several e-mails with Berger and Harriet. His communications are all related to his decision to keep Berger somewhat in the dark about what he is writing, who is source is, and what happened to him in Hedestad. He learns that Harriet has taken Henrik's place on the Millennium board and he urges Berger to trust her.
After a few weeks, Salander joins Blomkvist for an extended visit at his cabin. They once again fall into a comfortable routine. When Blomkvist tells Salander about how Wennerstrom forced one of his lovers to get an abortion, Salander is inspired to act against Wennerstrom. Finally, after weeks of work, Blomkvist plops his manuscript in Salander's lap for her review. He makes a few revisions, and Blomkvist and Salander return to Stockholm. Back in Stockholm, Salander and Berger meet. Berger is floored by the amount of information Salander was able to dig up and hugs her. Salander, seeing Berger's sophistication and elegance, is certain the two of them will never be friends.
Chapter 28 reveals a lot about Salander's often hidden emotional life and motivations. Even if she is not entirely aware of it, Salander is falling for Blomkvist. This chapter presents her time with Blomkvist in Sandhamm from her perspective, not Blomkvist's, so it's unclear whether Blomkvist feels the same way. Salander's growing tenderness to Blomkvist is revealed in her comfort with their living arrangements and her reluctant willingness to meet Berger at his request.
Whereas Blomkvist is driven by a need to expose truths, Salander is driven by a need to rectify injustices. When Salander learns about Wennerstrom's treatment of his lover, she lumps him in with all the evil men she's known, such as Bjurman and Martin Vanger. Although her plans for Wennerstrom are not yet clear, she surely has some sort of revenge in mind.