Knowing the story upfront I wanted to know how the pacing of this film was. I was surprised to find, that there is a lot of setup and getting to know the characters. Most of the time was spent showing how patronizing and abusive the behavior of the school director is towards his wife. There is even a clear hint that he rapes her. The ending is fantastic, but the aftermath seemed a bit tucked on.
Maybe they were trying to avoid the censors.
The scenes in the dining room were quite good as they immediately explained the hierarchy between everybody involved. When only the three main characters remain in the hall, there is some interesting mise-en-scene as the figures are carefully placed in the available space.
The final 15-20 minutes of the film are extremely gripping where this "crime" film suddenly becomes more of a "horror-thriller" crossover genre. And although I was prepared for something like that, I could barely watch it.