When Lisbeth Salander, the famed hacker from the Millennium series, receives a call from a stranger claiming to be her missing sister, she becomes embroiled in a dangerous conspiracy. As she delves deeper into the mystery, Lisbeth must confront her troubled past and use her skills to take down a powerful criminal organization.

Journalist Mikael Blomkvist is aided in his search for a woman who has been missing for 40 years by young computer hacker Lisbeth Salander. As they uncover clues and investigate further, they discover a connection to a series of murders and uncover dark secrets. Together, they must confront the truth and unravel the mystery.