The "Millennium Series" is a popular series of crime novels written by Swedish author Stieg Larsson. The series includes three main books: The Girl with the Dragon Tattoo, The Girl Who Played with Fire, and The Girl Who Kicked the Hornet's Nest. The story follows the investigative journalist Mikael Blomkvist and the skilled hacker Lisbeth Salander as they solve complex mysteries and uncover corruption. After Larsson's death, the series was continued by author David Lagercrantz, who wrote additional novels, including The Girl in the Spider's Web. The series has gained international acclaim and has been adapted into films and television series, further expanding its reach and popularity.