Mikael Blomkvist, convicted of libel against a powerful financier, is hired by elderly industrialist Henrik Vanger to investigate the decades-old disappearance of his niece Harriet from the isolated Hedeby Island. Blomkvist enlists Lisbeth Salander, a state-appointed ward with a photographic memory and exceptional skill as a researcher and hacker. What begins as a cold case investigation uncovers a history of family violence, Nazi sympathies, and serial murder stretching back forty years.