From amazon.com:

From the author of the number one international best seller The Girl in the Spider's Web, the new book in the Millennium series, which began with Stieg Larsson's The Girl with the Dragon Tattoo.

Lisbeth Salander, the girl with the dragon tattoo, the brilliant hacker, the obstinate outsider, the volatile seeker of justice for herself and others - even she has never been able to uncover the most telling facts of her traumatic childhood, the secrets that might finally fully explain her to herself. Now, when she sees a chance to uncover them once and for all, she enlists the help of Mikael Blomkvist, the editor of the muckraking investigative journal Millennium. And she will let nothing stop her - not the Islamists she enrages by rescuing a young woman from their brutality; not the prison gang leader who passes a death sentence on her; not the deadly reach of her long-lost twin sister, Camilla; and not the people who will do anything to keep buried knowledge of a sinister pseudoscientific experiment known only as The Registry. Once again, Lisbeth Salander and Mikael Blomkvist, together, are the fierce heart of a thrilling full-tilt novel that takes on some of the most insidious problems facing the world at this very moment.