Mikael Blomkvist is a financial reporter determined to restore his honor after being convicted of libel. Engaged by one of Sweden's wealthiest industrialists, Henrik Vanger, to get to the bottom of the long-ago disappearance of his beloved niece, Harriet - murdered, Vanger believes, by a member of his large family - the journalist heads to a remote island on the frozen Swedish coast, unaware of what awaits him. At the same time, Lisbeth Salander, an unusual but ingenious investigator with Milton Security, is hired to do a background check on Blomkvist, a job that ultimately leads to her joining Mikael in his investigation of who killed Harriet Vanger. Though Lisbeth shields herself from a world that has repeatedly betrayed her, her hacking skills and single-minded focus become invaluable. While Mikael goes face-to-face with the tight-lipped Vangers, Lisbeth plies the wired shadows. They begin to trace a chain of homicides from the past into the present, forging a fragile strand of trust even as they are pulled into the most savage currents of modern crime.

A journalist is hired by one of Sweden's richest industrialists to investigate the disappearance of his niece 40 years ago. With a female hacker assisting him, they uncover a secret history of murder and sexual abuse that puts their lives in danger.