I can't believe how bad they messed this movie up. The first two did a good job of recreating Hogwarts, and this one messed it up. What's up with the huge clock that all the sudden is right next to the infirmary? And I agree that without reading the book, the whole Sirius thing wouldn't make a bit of sense. I guess they figure that anyone who's going to see the movie has read the book.
My mom says I shouldn't talk to conservatives.