Goblet of Fire opens with a bunch of murders, which shows us right off the bat that J.K. Rowling is getting darker with this installment. Fifty years prior, the town of Little Hangleton was shaken by the killing of the entire Riddle family: a man, woman, and their adult son. No one could figure out the cause of death, but the entire village is sure that Frank Bryce, the Riddles' gardener, is the murderer. Even so, Frank Bryce has stayed on as the caretaker for the Riddles' former house. One night, he sees a light on at the Riddle house and goes to investigate. He finds a wizard (Wormtail) and someone else – a thing. The thing orders Wormtail to murder Frank Bryce. And 200 miles away, Harry Potter wakes up. He has seen the whole scene. The thing sitting in that chair must have been Harry's enemy, Lord Voldemort, though it seems impossible since the Dark Lord is still supposed to be a spirit without a body… An ominous beginning to this installment of the Harry Potter series.
This dream – and Harry's growing pain from the lighting bolt-shaped curse scar on his forehead – demonstrate that Lord Voldemort is gaining strength once again. Harry doesn't know what to do about any of this, so he writes to his godfather, Sirius Black. Then, Harry's best friend Ron Weasley rescues Harry from a boring summer vacation with his awful Muggle relatives to go to the Quidditch World Cup.
At the Quidditch World Cup game itself, Harry, Ron, and their other best friend, Hermione Granger, wind up enjoying themselves quite a bit. But then, the night of the match, there's a vicious, public prank committed by a bunch of guys in robes and masks – former Death Eaters, supporters of Voldemort.
True mayhem breaks out when someone casts the Dark Mark into the sky, a well-known symbol of Voldemort himself. Ministry of Magic representatives catch a house-elf, Winky, holding the wand that cast the Dark Mark. To make matters worse, the wand is Harry's – he dropped it in the rush when the Death Eaters appeared. The house-elf in question belongs to the household of Mr. Bartemius Crouch, a very strict and upright member of the Ministry of Magic. Even though it seems impossible that Winky cast the Dark Mark herself, Mr. Crouch still expels poor Winky from his household.
When Harry, Ron, and Hermione wind up back at Hogwarts School for Witchcraft and Wizardry for the year, they discover that none other than Winky is living in the Hogwarts castle kitchens. So is Dobby, a house-elf friend of Harry's who first appeared in Harry Potter and the Chamber of Secrets. Hermione feels that the house-elves are basically slaves to the wizarding families they serve, so she grows politically active as she tries to come to their rescue. She starts S.P.E.W. – the Society for the Protection of Elvish Welfare – and makes Ron and Harry join. But everyone keeps telling her that the house-elves are happy to act as servants for wizards, and she shouldn't force her help on people who don't want it.
Besides Hermione's growing political enthusiasm, three major things happen at Hogwarts during the school year. The first is the appointment of a new Defense Against the Dark Arts teacher yet again – this time, one Alastor "Mad-Eye" Moody. Moody is an experienced Dark wizard fighter who seems committed to teaching Harry as much as he can, and Harry grows to like and trust the prof.
The second major thing going on this year is the Triwizard Tournament, a competition between the three European wizarding schools of Hogwarts, Beauxbatons, and Durmstrang. Each of these schools will have one champion enter the competition, whose name will be selected by the magical Goblet of Fire. Students have to be over seventeen years old to enter, though, so that rules out Harry, Ron, and Hermione (but who are they to follow the rules?).
At Halloween, each school's representative is announced. For Durmstrang, it's Viktor Krum (a world-class Quidditch player, who played in the World Cup final), for Beauxbatons, it's Fleur Delacour (a stunningly beautiful girl), and for Hogwarts, it's Cedric Diggory (a loyal, dependable Hufflepuff guy). Then, mysteriously, Harry gets selected as a fourth champion. No one knows how: Harry is too young and couldn't have put his own name in the Goblet of Fire! But once he has been selected, he has no choice but to participate in the Triwizard Tournament as well. This, of course, creates friction between Harry and most of Hogwarts, especially Ron. They all think that he must have put his own name in, and that he's just looking for more attention and glory. Harry starts getting more and more stressed.
Adding to the stress is the third major thing that happens during Harry's fourth year at Hogwarts: Rita Skeeter. Rita Skeeter is a reporter for the Daily Prophet. She likes to sell stories, and she's perfectly happy to twist the facts if she thinks they will make for a more sensational read. She publishes a really exploitative article about Harry in the Triwizard Tournament, claiming that he still cries whenever he thinks of his dead parents. Harry is furious and embarrassed. Fortunately, the article doesn't put Harry off his game: he manages to get through the first Triwizard Tournament task – with a Hungarian Horntail dragon, no less – pretty smoothly. Afterwards, he even makes up with Ron. Double score!
Even though Harry and Ron are again best friends, the stress of Harry's life doesn't go down. Nope – now, he's got hormones to deal with. As part of the Triwizard Tournament tradition, there's going to be a Yule Ball during the winter holidays. Harry has to ask someone to go with him. He invites a Ravenclaw girl he has a crush on, Cho Chang, but turns out she's already going with Cedric Diggory. Ron, in a fit of insanity, asks beautiful Fleur Delacour. But she's not interested. Hermione is going with Viktor Krum – something that really bothers Ron, though he's too emotionally dense to figure out why. So Harry and Ron wind up going with twins Parvati and Padma Patil, which doesn't make any of them very happy. Ron and Hermione end the night by having a screaming fight about Viktor Krum, and even when they make up, there's still simmering tension between them.
Rita Skeeter continues to make trouble: she publishes an article telling the world that Hagrid, Harry's good friend and teacher of Care of Magical Creatures, is vicious half-giant. This is a huge deal in the wizarding world, and Hagrid almost quits his job because of it. Fortunately, Harry, Ron, and Hermione manage to convince him not to leave. But Hermione is so furious that she resolves to figure out how Rita Skeeter is finding out all of this private information she shouldn't have any way of knowing.
Meanwhile, Harry keeps moving through the Triwizard Tournament. He and Cedric have started exchanging tips for each of the tasks, and, with the help of Mad-Eye Moody and Dobby the house-elf, Harry is tied for first place with Cedric after the second task. The third task is supposed to take place on June 24th. They're going to have to get through a giant maze, and at the center of the maze is the Triwizard Cup. Whoever reaches the cup first wins.
On the day of the third task, Harry, Cedric, Viktor, and Fleur all start to move through the maze. Harry overhears Fleur scream and assumes that she's out of the tournament. Then, he is shocked to hear Viktor casting the Cruciatus Curse (an illegal spell that causes intense pain for those on the other end of it) on Cedric Diggory. So Harry stuns Viktor, and he and Cedric keep going through the maze. Harry gets injured by a giant spider just before reaching the Triwizard Cup, but Cedric offers to let Harry have the prize anyway to thank Harry for all of his help during the competition. Harry wants to take the Cup at the same time as Cedric, so the two of them can tie in the competition. Cedric agrees, and he and Harry grab the Cup at the same time.
But the Triwizard Cup magically transports both Harry and Cedric to a graveyard. Suddenly, Cedric is murdered before Harry's eyes with the Killing Curse, Avada Kedavra. Yep – Wormtail and the thing that is Voldemort are both in the graveyard. This whole Triwizard Tournament was organized just to bring Harry to this graveyard, where Voldemort's father, Tom Riddle, has been buried. Wormtail puts together a potion made out of Tom Riddle's bones, Harry's blood, and Wormtail's own severed hand to bring Voldemort back to life and health. With this new power, Voldemort gets his body back.
With Voldemort's rise, his Death Eaters appear in the graveyard around him. Voldemort sets up a "duel" between Harry and himself, although it's clear that Voldemort is absolutely confident in his own triumph. But something weird happens when Voldemort and Harry's wands face each other: a beam of light connects both wands, and the previous spells that Voldemort has cast start coming out of his wand. This means that the ghosts of the people Voldemort has murdered start appearing in reverse order out of his wand: Cedric Diggory first, then Frank Bryce, then Harry's mother, and then Harry's father. The shock over the appearance of these ghosts gives Harry the time he needs to rush over to Cedric's body and then grab the Triwizard Cup. The Cup transports Harry and Cedric's body back to Hogwarts…to the shock of everyone they appear before.
Harry is ushered away from the maze by Moody. Slowly, Harry starts to realize that something is wrong with Moody. Moody tells Harry that he was the one who put Harry's name in the Goblet of Fire. And he has been helping Harry get through the three tasks because he wanted Harry to reach the Triwizard Cup first – so that he could be transported to Voldemort's father's graveyard and be used in a spell to bring Voldemort back to life. Moody then raises his wand to kill Harry, but three Professors – McGonagall, Dumbledore, and Snape – all stun Moody before he can do it. As they watch, the unconscious Moody slowly turns back into his true form: Bartemius Crouch, Jr., who was convicted thirteen years before of being a Death Eater and for horribly torturing Frank and Alice Longbottom (Neville Longbottom's parents).
Barty Crouch, Jr. was smuggled out of prison by his father, Bartemius Crouch, Sr., as a favor to his dying mother. But he has been kept under house arrest under the care of their house-elf, Winky. Winky begged and pleaded that Barty Crouch, Jr. be allowed to go the Quidditch World Cup as a reward for good behavior. It was at the Quidditch World Cup that Barty Crouch, Jr. escaped Winky and cast the Dark Mark that frightened so many wizards. After getting free, Barty Crouch, Jr. made contact with Lord Voldemort, concocted this whole Harry Potter in the Triwizard Cup idea, and substituted himself for the real Moody using a disguise potion called the Polyjuice Potion. Meanwhile, the real Moody has been living locked up in Barty Crouch, Jr.'s trunk for the past year – yikes.
Harry gives his evidence that Voldemort has risen again to Professor Dumbledore, who informs Cornelius Fudge, the Minister of Magic. But Fudge absolutely refuses to believe it. He's in firm denial, and manages to keep any mention of Voldemort out of the Daily Prophet. There's no additional proof besides Harry's word because Barty Crouch, Jr. has been killed in Ministry custody: a magical creature called a Dementor ate his soul. So it's just Harry's word against Fudge's, and Fudge has all the power.
At the end of school Leaving Feast, Professor Dumbledore decides to set his Hogwarts students straight. He explains to them that Lord Voldemort murdered Cedric Diggory, and that Voldemort is back again. But several students – troublemakers like Draco Malfoy – refuse to acknowledge Professor Dumbledore's speech.
On the train to London for the summer holidays, Harry, Ron, and Hermione talk about the past year. Hermione finally gets to explain that she's figured out how Rita Skeeter has been spying. Rita Skeeter is an unlicensed Animagus, someone who can change into an animal. Animagi are all supposed to register at the Ministry, but Rita hasn't. Her form is a beetle – a convenient size for overhearing private conversations. So Hermione has agreed not to share Rita's secret with the Ministry of Magic as long as Rita Skeeter doesn't publish any more nasty things about people for at least a year. Ron promises Harry that he can come and visit the Weasleys later in the summer. Until then, Harry should take care of himself. Harry says good-bye to Ron and Hermione until the next school year.