Moody's revelations upset the trust that we and the students at Hogwarts have placed in Moody. This turn of events is possibly the greatest disappointment of the book, as Moody previously seems a thoroughly solid, trustworthy character. The unveiling of him as a villain leaves everybody's instincts, including those of Dumbledore, in an insecure state. He fools all of the characters in the book, and leaves the greatest wound. In the previous three books, the great villains are surprising. But with the false security of Mad-Eye Moody, nothing seems safe. The most we can hope is that the real Moody, fast asleep in the trunk, will be when he awakens as eccentric and endearing as the false Moody.
Harry's homecoming as Triwizard Champion is, needless to say, not at all how Harry daydreamed it would be in the months before his name was entered into the Goblet. The deception of the tournament is a terrible example of the malicious workings of Voldemort. Rather than being rewarded with celebration, the winners' reward was death. The major tournaments in this book—Quidditch and the Triwizard Cup—end frightfully due to some work of a Voldemort supporter.