Throughout the pages of Goblet of Fire, Harry also has to confront the horrors of growing up.
At most, he was aware that Professor Quirrell and maybe a few others wanted Voldemort to return, but not that there was a powerful and motivated group of people who not only want Voldemort to return to power, but that have been doing their part in secret to keep his cause alive. Prior to Goblet of Fire Harry mostly knew that Voldemort was evil, killed his parents, and was trying to return to the land of the living. This is the book where Harry meets those who want Voldemort to return to his evil ways and the entire world is thrown off its axis. The absolute best of the best, Harry Potter and the Goblet of Fire is not only the pivotal story in the saga for the Harry/Voldemort dynamic, but it represents a turning point for just about every character.