Affleck doesn't say much in the trailer, which hit the web on Monday, except that he "did not kill my wife." But it does feature a melancholy Richard Butler cover of the classic love song, "She."
Fans of the book should prepare themselves for a departure from the novel's original ending. Flynn, who penned the script, wrote an alternative conclusion for the film adaptation.
"There was something thrilling about taking this piece of work that I'd spent about two years painstakingly putting together with all its eight million Lego pieces and take a hammer to it and bash it apart and reassemble it into a movie," she told Entertainment Weekly earlier this year.
Gone Girl hits theaters October 3.
[H/T Deadline, CBS News]