Lolita a while back. And I was surprised at the plot.
In the movie I watched (the 1962 version directed by Stanley Kubrick; there's a 1997 version that apparently has the same plot), a middle-aged professor becomes infatuated with the 14-year-old daughter of his landlady. That I knew going in.
What surprised me is what happened. The professor (named Humbert Humbert) marries the landlady (presumably to be near Lolita) but then the landlady sends Lolita off to summer camp and says after that she's going to boarding school. Humbert plots to kill the landlady, but then she is killed in an accident or suicide when she is hit by a car. Humbert goes to the summer camp to pick up Lolita and on the way back, they are forced to spend a night in a hotel room together, even though he has a cot. But in the morning, they apparently have sex. The rest of the movie is about how their relationship deteriorates as she's a silly little girl who cheats on him with another older man. Then she disappears and he doesn't see her for years. I won't spoil the whole movie by tell where he finds her (and in what condition).
Which wasn't the movie I thought it would be at all. I thought it would go more like this: Humbert Humbert is a successful professor, married, and somehow meets Lolita. He become obsessed with her, and tries to be with her. This destroys both his marriage and career. But he doesn't care because he is so focused on Lolita. Finally, he manages to have a relationship with her, that might not include sex, and he finds out that she is a silly, shallow little girl (as 14 year olds tend to be).
I was so upset by the actual plot of the movie (which I assume follows the plot of the book because the movie was written by Vladimir Nabokov, who wrote the book) that I am seriously considering writing a novel with the plot I imagined. But that's not the kind of novel I write. Plus, what would I name the girl? I couldn't call her "Lolita."
I guess I'll think about it more.