Summer with Monika has a classic art film story behind it: Bergman came up with the idea quickly, having gotten some money, and he just took his few actors and crew on a summer vacation with very little planning involved. What results is a simple story, but one that is very mature and emotionally complex. Two teenage lovers escape the tyranny of their parents. Stealing a boat, they travel around the southern islands of Sweden together, revelling in their adolescent lust. A few things happen along the way, but they aren't really worth mentioning. Not that these events are unimportant, only that to describe them would not be useful here; they ought to be experienced as they happen.
What makes this film a masterpiece is the third act. Teenage love is often so idealized by artists, born from an air of irresistable nostalgia. Maybe Ingmar Bergman was too much of a pessimist for his characters to find neverending happiness by the time the film fades out. Harriet Andersson, a Bergman regular, of course, plays Monika. There is a love in her, and she may even really love Harry (played by Lars Ekborg) when they set out together. On the other hand, part of it is she just wants the experience of an adventure, of independence from her cluttered and sad homelife and parents, of love, and, not least of all, of sex. Monika is, first and foremost, a sexual being. Andersson is not exploited, though, as she so easily could have been (French actress Brigitte Bardot provides the best example of just how an actress' career can be harmed by these kinds of highly sexual roles). Andersson arouses the audience, but Bergman is careful (as he is with all of his women) not to make her into some cheap male fantasy. We want Harriet Andersson, yet we realize that she is not to be had. She is her own person.
This manifests itself in a pretty nasty way in the third act. Eventually, as the summer begins to fade, Harry decides that the two of them cannot spend the rest of their lives drifting around on a boat. They also have realized that Monika has become pregnant. Bergman thus eschews the type of ending where the two return home, maybe in love maybe not, and that's that. Instead, he gives these two characters a reality check. Harry jumps into it with gusto, marrying his sweetheart and getting a decent job. When his child is born, he is overjoyed. Unfortunately, Monika (who is two years younger than Harry, at 17) cannot make the same leap. This monotonous, routine life which she was hoping to escape falls back down on her. The fact that she has a child annoys her: no longer is she free to do what she chooses. And her lust is now left unsatisfied: Harry sees her as the beautiful mother of his child, not so much as his lover anymore. Ultimately, because Harry is away so much with his work, Monika's lust breaks loose. In the film's most memorable scene, she picks up a new boyfriend at a bar. Bergman allows her to look straight into the camera, one of the earliest examples of a filmmaker breaking the fourth wall. Monika looks into our eyes, and we see the pain, fear, and loneliness she has acquired. The shot is held for what seems like forever, even though it comprises only a few seconds.
Monika leaves Harry and their baby. The film ends with Harry alone, staring at himself and his child in the mirror. He is hurt, that is certain, but I do not believe that he judges her too harshly. After all, he does understand Monika and her temperament. As he remembers the beauty of the summer he and Monika shared, he cradles in his arm the only physical evidence left of that time. It's a sad ending, but, with the warmness we see in Harry's expression, we know that the child will be much loved by its father. Life continues.