In Stockholm, Sweden, journalist Mikael Blomkvist, who is the co-owner of Millennium magazine, finds himself facing the repercussions of a libel case that he has just lost against the corrupt businessman Hans-Erik Wennerström. Meanwhile, Lisbeth Salander, a remarkably skilled but troubled researcher and hacker, performs an exhaustive background check on Blomkvist at the behest of the wealthy industrialist Henrik Vanger. This investigation is not just a routine task; it comes with the promise of revealing critical information about Wennerström.
Blomkvist takes on the challenge of investigating the mysterious disappearance and presumed murder of Henrik’s great-niece, Harriet Vanger, which occurred four decades earlier. He moves to the Vanger family's estate, where he soon uncovers a notebook filled with names and numbers that have baffled everyone who has tried to decode them. The gravity of Harriet's case intensifies when we learn of the circumstances surrounding her disappearance in 1966—during a family gathering on a Swiss island for their annual board meeting, an accident on the only bridge prevented any communication or escape for a full 24 hours.
Lisbeth Salander, who is under state guardianship due to her mental health issues, is assigned a new guardian, Nils Bjurman. This relationship quickly turns abusive, as Bjurman exploits his position to coerce Salander into sexual favors. However, Salander, resourceful and resilient, manages to turn the tables on him, recording his misconduct and punishing him by taking control of her own finances.
As Blomkvist digs deeper into the Vanger family history, he learns that Henrik's three brothers were Nazi Party members, and Harriet was the daughter of Gottfried, who passed away shortly before her disappearance. Blomkvist discovers that Harriet’s Bible contains a list of five names that seem to correlate with her mysterious fate. After consulting police inspector Morell, who informs him that the names have defied interpretation, Blomkvist realizes that they might be references to Biblical passages.
His investigation takes a new turn with the insights from his daughter, who helps him uncover that the names indeed relate to certain victims of unsolved murders dating back to 1947-1967. Many of these women have Hebrew names, linking them with the Vanger family's past and their reported anti-Semitism. As Blomkvist and Salander collaborate on this chilling puzzle, they find that their professional relationship grows into a romantic one.
Amid the unfolding drama, Blomkvist is shot at while investigating, and the mystery deepens as the identities of the victims surface. Through Salander's adept research, they determine that Harriet's brother, Martin, might be involved in the family's dark legacy. The tension peaks when Blomkvist confronts Martin, resulting in a life-or-death showdown that Salander intervenes in, demonstrating her fierce loyalty.
After a gripping chase, Salander brings Martin to justice, revealing her own traumatic past intertwined with themes of familial abuse and resilience. Ultimately, they track down Harriet, who has been living under the identity of her cousin, Anita. She shares her harrowing history of abuse, leading to a cathartic reunion with Henrik.
As Blomkvist’s professional journey closes with him publishing damaging revelations about Wennerström, the story's emotional depth deepens. Salander meticulously hacks into Wennerström’s accounts, ensuring the long-standing criminal faces the consequences of his actions. Yet, in a moment of heartache, she witnesses Blomkvist with his partner Erika Berger, leading to her own retreat from a moment that could have brought them together.
Through intertwining lives, trauma, and revelations, the film unravels a tapestry of dark familial secrets, resilience under oppression, and the relentless pursuit of truth.
