Harry Potter and the Goblet of Fire

Essential, and the hinge of the series. Everything before it is a school story with a threat somewhere in the background. The last ten minutes end that permanently: a student is killed, offhandedly, in front of Harry, and the villain the first three films kept at one remove is standing in a graveyard in a body.

The adaptation problem is the famous one. The book is more than twice the length of the third and the film is only fifteen minutes longer, so entire institutions are cut. House-elves are gone, the political subplot is gone, and the Quidditch World Cup is a crowd shot and a fire. Mike Newell keeps the three tournament tasks and the dance, which is the right call and leaves the film lurching between enormous set pieces.

What it does well is adolescence. The Yule Ball sequence, with two boys failing to ask anybody out and then standing miserably at the edge of a room, is the most recognisable thing in the series, and Newell plays the whole middle act as a British school comedy before the ending arrives.

The dragon is the best effects sequence in the eight films and the graveyard is the best-directed scene. Ralph Fiennes arrives with no nose and complete conviction. Watch it, and be aware that the series is a different thing afterwards.