The first two attempts to bring Rowling's work to the big screen--Harry Potter and the Sorcerer's Stone and Harry Potter and the Chamber of Secrets--were both directed by Chris Columbus, the corporate sentimentalist who gave us such explorations of contemporary domesticity as Stepmom, Mrs. Doubtfire, Adventures in Babysitting, and the Home Alone movies.
For no other reason than the fact that the directorial reins of the Harry Potter series have been passed from the hands of Chris Columbus, as mild and unthreatening of a filmmaker as you could possibly imagine (besides the first two "Potter" films, he also directed the first two "Home Alone" movies, "Bicentennial Man" and "Adventures in Babysitting"), to Alfonso Cuaron, who received considerable acclaim for such bold works as the visually sumptuous "A Little Princess" and "Y Tu Mama Tambien", critics have been describing "Harry Potter and the Prisoner of Azkaban" as being the "darkest" entry of the series.