Gone Girl, both the book which has sold 8.5 million copies and the movie, has touched a nerve. As I settled into my seat to watch the film with a friend, clusters of women chatted around us. I realized that the movie had inspired many girls’ nights out.

Using the unscientific method of listening to theater murmurings, I learned several things about the audience. First, most of the women had read the book and knew what to expect. Second, most of the men in the audience had not read the book, and the plot took them by surprise. Finally, the women in the theater shared a subtle current of delight over the agency of the main character.

Ben Affleck and Rosamund Pike star as the gorgeous Nick and Amy Dunne. The story opens on their fifth anniversary, when Nick comes home and finds evidence of violence in his living room. His beautiful wife is missing.