"Harry Potter and the Goblet of Fire" is the only Harry Potter book to win a Hugo, the premier award for science fiction and fantasy literature. This book also continues the trend of the Harry Potter books to not only get larger but more adult as the series goes on. In this book one of the character is killed and Voldemort is returned to full power.
One of the main things that this book adds too is the size of the Harry Potter universe. With the calling of a tri-wizard tournament students from two other schools arrive in Hogwarts spending time with the students. These students come from a French wizarding school and a Bulgarian wizarding school. This adds a great deal of color to the characters in this book and interesting new ideas for the characters to interact with.
This book also has more romance than other books. With a Yule ball that allows the kids in the wizards school to have the same worries and troubles about relationships that kids in ever school does. In addition to this Harry is forced to act on his own more in this book. Ron is angry with him much of the book and even when he isn't the tri-wizard tournament is a competition that he is in alone.
Much of the action in this book takes place in that tournament. With magical tests that are meant to be passed but difficult, and rules that say Harry is too young to enter the tournament that had long been banned because it was too dangerous there is a genuine feel of danger one that is increased considerably when one of the characters in this book dies.
J.K. Rowling says that this was the most difficult of the books for her to write. As she was working on it she discovered that there was a major plot hole and had to rewrite the ninth chapter thirteen times. This doesn’t show in the writing though as it is as smooth as any of the books.
With each new Harry Potter there is at least one new professor at Hogwarts. In this book it is Mad Eye Moody an Auror and friend of Dumbledore who teaches Defense against the Dark Arts and goes farther than the others showing the students the three unforgivable curses, including the killing curse. A curse which only Harry Potter has survived.
This book is a turning point in the Harry Potter series. Though much of the book it has the same feeling as the first books but at the end this becomes a considerably more adult story as Harry is forced to face something much more dangerous than a tournament. Parents should read the end of this story before young children but for most able to make it through a book this size it should be appropriate.