Some things I didn't understand (Spoilers)
I watched the movie recently and had a few doubts about it.
The director of the school didn't seem like she had left the room she was in in a long time. So didn't the students who had been at the school for 2-3 years think it odd that they had never seen the director?
Again, since the director seemed to spend all her time in that room, why exactly would Sarah have heard the dance school director next to her room? Also, why would Sarah and Suzy have heard her in the hall that night.
What exactly was the purpose of the scene where Suzy gets dazzled by the cook? I don't think it was revisited.
Why were they keeping Suzy drugged? How was she different from any of the other students?
There are probably other points, but these are the ones I could think of off the cuff.
Not sure if I didn't pay enough attention to the movie, but I thought a lot of points were unexplained.