After decades without one, a new Triwizard Tournament has been announced and Hogwarts is hosting. Harry is too young to compete but, much to everyone's surprise - including his own - his name is selected as an additional champion. Harry suspects Voldemort's influence, but he must first survive the competition's three deadly tasks. 
 So far in the series, Harry&co. have been children, and their friendship has been fairly uncomplicated. Hermione was dealing with a lot of stress in The Prisoner of Azkaban, but they've otherwise been able to depend on each other while they face external foes. In The Goblet of Fire, however, one of the enemies they face is on the inside - puberty. Suddenly, gender becomes important, and the dynamic between Hermione and her two male friends starts to shift and require redefining. All this is further complicated when the Tournament brings with it the Yule Ball, forcing Ron and Harry to find dates. 
 I found The Goblet of Fire to be the most self-aware of the series so far. While Harry's fame has been an issue throughout the series (and the reason he was placed with the Dursley family in the first place), this is the first time that it has become such a central theme. Harry - who seems to always be at the centre of everything - is contrasted with Ron, a youngest son starved for attention. 
 One thing I love about this series is how many "teachable moments" there are. Issues are raised and attention called to them, but solutions aren't explicitly given. This leaves a lot of room for the reading of the series to be a family activity, with the opportunity for plenty of discussion. 
 The book does suffer from many of the same plotting issues that I've already covered, with Harry's grown-worthy chance discoveries that just happen to move the plot forward and exactly the right time. Nevertheless, the series is strong enough in other areas to compensate for this one failing.