Unusually, Chapter 12 begins without entering directly into a scene. The chapter opens with a description of the Swedish legal system and insight into how Salander became a ward of the state. The young woman was one of many adults who, due to a variety of mishaps and mental problems, wound up entrusted to either trustees — voluntary, less restrictive mentors — or guardians, caretakers who can take complete legal control (including financial control) of their ward's life. Because of her troubled youth, her inability to get along with others, and her refusal to discuss her problems or point of view, Salander first had Palmgren, then Bjurman as a guardian. Salander is unsure how to proceed now that Bjurman has assaulted her and taken control of her finances. Salander, having had trouble with the police before, doesn't see turning to authorities as an option. She returns home after her meeting with Bjurman and wrestles with the problem.
The narrative shifts to Cecilia and Blomkvist lounging in Cecilia's bed after making love. They share a few drinks and talk about Harriet — off the record. Cecilia says that she never knew Harriet very well, but that both Harriet and Martin were deeply affected by the dysfunction of their parents, and their father's (Gottfried) drowning. Cecilia adds that she thought Martin was more mentally unstable than Harriet when they were growing up.
Next, the action shifts back to Salander and her turmoil over what to do next. She first considers contacting one of her friends, but she doesn't find any good options among them. Plague wouldn't be of any help, nor would any of her current or former lovers. Moving on, she considers going to Armansky, knowing that he was sincere in his promise to help her if she ever needed assistance. However, she worries Armansky would be too attentive to her if he took over her guardianship. Finally, she falls back on someone she can always rely on — herself.
Chapter 12 compares and contrasts both Harriet and Salander and Harriet and Martin, in addition to foreshadowing events to come. First, Cecilia reveals important elements of both Harriet and Martin's upbringing and the effects on the sister and brother. She says that, despite some of the changes in Harriet's behavior, Harriet seemed fairly stable. Her tragic flaw, according to Cecilia, appeared to be her refusal to open up to anyone about her life. This flaw is similar to Salander's. Because of the difficult events in her life, Salander, too, feels her best option is to work through things alone.
Harriet and Martin also are contrasted in this section. Harriet, again in Cecilia's depiction, seems to be the more stable child, whereas Martin was more "antisocial" and "introverted." Here, new information about these two siblings is revealed, and more depth is added to Martin's character. Until now, he has seemed like a likable but rather incompetent CEO of Vanger Corporation, unable to save the company from financial suffering. Cecilia's comments about him indicate that he may be more troubled and less stable than he appears.
Foreshadowing also occurs as Salander decides to take matters into her own hands. The chapter ends with the indication that, if she does so, the result will be highly troublesome for Bjurman. Leading up to this chapter's review of her childhood, Salander has been shown to be unafraid of using violence to solve problems. For instance, when she was picked on by a bigger boy in her childhood, Salander would continue fighting, unafraid, and unwilling to back down despite her lack of physical strength. Her violent past, coupled with her improved ability to consider consequences, may result in fierce revenge against Bjurman.