I recall the controversy as this was released. Alfonso Cuarón consciously decided to darken this film, and the light-hearted stories of the first two are replaced by an edgier approach to this tale for our wizarding trio. The world's most wanted wizard "Sirius Black" (Gary Oldman) escapes from "Azkaban" allegedly bent on the destruction of "Harry". The script has more by way of addition to the original book, but in a complementary - not detracting way. As the children grow into young adults, we are exposed to a scarier side of their existence - the "Dementors" that are supposed to protect the innocent and the "Boggart" all serve to introduce a physical fluidity to this shape-shifting environment of peril in which they now exist. The presence of "Valdemort" becomes more omnipresent and there is so much more substance to the stories now. Sir Michael Gambon takes over the role of "Dumbledore" without quite the presence of Richard Harris, but we can tell now that this series is heading for murky, dangerous, waters...