The Girl with the Dragon Tattoo recap

Disgraced financial journalist Mikael Blomkvist, reeling from a libel conviction, is hired by retired industrialist Henrik Vanger to solve the decades-old disappearance of his grand-niece Harriet, who vanished from the family's isolated island when it was cut off by a bridge accident. Living on Hedeby, Blomkvist teams with Lisbeth Salander, a gifted, damaged hacker who had investigated him. Together they discover that a string of coded numbers in Harriet's notebook point to a series of ritual murders of women stretching back decades, and that the killer is Harriet's own brother, Martin Vanger, who was continuing crimes begun by their abusive father Gottfried. Salander saves Blomkvist from Martin's torture chamber, and Martin dies fleeing. Harriet is found alive in Australia: she had killed her father in self-defense and fled her brother's abuse. Salander then uses her hacking skills to destroy Wennerstrom, exposing his criminal empire and secretly draining billions from his accounts, clearing Blomkvist's name.

Mikael Blomkvist, co-owner of the Stockholm magazine Millennium, is convicted of libel after publishing accusations of fraud against the financier Hans-Erik Wennerstrom. The verdict fines him, threatens prison, and damages his magazine, so he steps back from Millennium. Separately, the reclusive investigator Lisbeth Salander, who works for Milton Security, is hired to compile a detailed background report on Blomkvist. That report is commissioned on behalf of Henrik Vanger, the retired patriarch of a wealthy industrial dynasty, who summons Blomkvist to his estate on the remote northern island of Hedeby. Vanger offers him a large sum, plus damaging information about Wennerstrom, to spend a year ostensibly writing a Vanger family chronicle. His real request is that Blomkvist reinvestigate the disappearance of his grand-niece Harriet, who vanished as a teenager decades earlier during a family gathering, on a day when an accident had sealed the island off from the mainland. Vanger is convinced she was murdered by a member of the sprawling, feuding family.

Blomkvist moves into a cottage on Hedeby and begins immersing himself in the Vanger family's history and the old case files. He learns that Harriet disappeared from what amounts to a locked island: the bridge to the mainland was blocked by a tanker accident, so she could not have simply left, yet no body was ever found. He works through decades of photographs, family grievances, and secrets, and grows close to Cecilia Vanger, a relative with whom he begins an affair, though she is guarded about the day Harriet vanished. He puzzles over a cryptic list in Harriet's old datebook, a set of names paired with numbers whose meaning eludes him. Meanwhile Salander's own life takes a dark turn: placed under a new legal guardian, the lawyer Nils Bjurman, who abuses the power he holds over her finances and freedom, she plans and carries out a calculated, brutal revenge that reasserts her control over her own life.

Impressed by the background report done on him, Blomkvist tracks down its author and recruits Lisbeth Salander as his research partner. Her skills transform the investigation. Together they crack the meaning of Harriet's coded list: the numbers are Bible references, and the names are linked to a series of unsolved, ritualized murders of women scattered across Sweden over many years. It becomes clear that Harriet had stumbled onto a serial killer, and that the killings are connected to the Vanger family itself. As Blomkvist and Salander map the pattern of victims and dates, the danger sharpens. They realize the murders did not stop with Harriet's disappearance and that whoever is responsible is close to home, drawing the two investigators toward a confrontation with someone inside the family they have been living among.

The investigation converges on Martin Vanger, the outwardly genial company chief, who is exposed as a serial killer continuing crimes begun by his and Harriet's father, Gottfried. Martin captures Blomkvist and traps him in a hidden, soundproofed killing room beneath his house, boasting of years of murders before Salander arrives and overpowers him, saving Blomkvist's life. Martin flees by car and dies in a head-on crash. Salander investigates his home and finds documentation of his victims. Following new leads, Blomkvist traces Harriet, discovering that she is alive and living in Australia under another identity. She reveals the truth she had hidden: as a girl she had been abused by her father Gottfried and killed him in self-defense, then, realizing her brother Martin was equally dangerous, she secretly fled the island and never returned, letting the family believe her dead.

Harriet returns to Sweden and reclaims a place in the family and the Vanger Corporation, while Henrik Vanger finally has his answer. Blomkvist, still needing to clear his name and honor the promise of evidence against Wennerstrom, works with Salander to finish that fight. Salander, using an assumed identity and her hacking expertise, penetrates Wennerstrom's financial empire, gathering proof of his criminal dealings and secretly transferring roughly two billion kronor out of his accounts into her own control. Millennium publishes Blomkvist's devastating expose; the scandal breaks, Wennerstrom flees the country, and he is later found murdered abroad. Blomkvist's reputation and the magazine are restored. Salander, who has developed genuine feelings for Blomkvist, goes to his home to give him a Christmas gift, but sees him arriving with Erika Berger. Hurt, she throws the present away and turns from him, leaving her feelings unspoken and the two of them apart as the book ends.

Blomkvist and Salander solve the Harriet mystery: her brother Martin was a serial killer who had inherited and continued the crimes of their father Gottfried, murdering women for years. After Salander rescues Blomkvist from Martin's soundproofed killing room, Martin dies in a car crash while fleeing. Blomkvist tracks Harriet to Australia, where she has lived under a false identity; she reveals that as a girl she drowned her sexually abusive father and then fled the island to escape Martin. Harriet returns to Sweden and takes a leading role in the Vanger Corporation. To settle the score with Wennerstrom, Salander poses as an investor, hacks his accounts, and both exposes his vast criminal network and steals roughly two billion kronor, which she keeps. Millennium publishes Blomkvist's devastating expose; Wennerstrom flees and is later found murdered. Blomkvist's reputation is restored. Salander, having fallen for Blomkvist, goes to give him a Christmas present but sees him with Erika Berger and, wounded, throws the gift away, leaving their relationship unresolved.