The concept of the binding magical contract is introduced. Is this the same as what Snape undergoes in book 7? What would the consequences be if they pulled out? Would they die? I find that the magical world is much more lenient about placing heavy responsibility and heavy sanctions on young people. I suppose that is part of the "great power" deal.

Also, Dumbledore uses his legilimens powers to ascertain whether Harry had done it or not. I have never noticed that before, but it seems very obvious now. It makes more sense than unflinching belief in Harry's honesty.

Mr Crouch is under the imperious curse already, isn't he? He is acting strange, uninterested and is described as seeming to emerge from "deep reverie". He looks ill, and Dumbledore is concerned. It is strange that Dumbledore does not look into it more closely.

The way Hogwarts treats Harry is of course reminiscent of both how he was treated in book 2 and how the gardener was treated by the people in the village in chapter 1. It is another of Rowling's major themes. I like how she develops it, even if I get a little tired of Harry's whining.

Gregorovitch is introduced as a famous wandmaker.