Foreshadowing / Harry Potter and the Goblet of Fire

• In the first chapter, "I will allow you to perform an essential task for me, one that many of my followers would give their right hands to perform..."
• Voldemort knows that Frank Bryce is lying about having a wife who knows he's gone to confront intruders and will call the police if he doesn't come back. The next book reveals that Voldemort has telepathic powers.
• The beginning of the book starts off with a nightmare where Harry is dreaming about Voldemort killing an old man, which later turns out to be a psychic dream of an event that actually occurred. This lays the groundwork for Occlumency and the Mental Connection that Harry and Voldemort have that is further explored in Book 5.
• During the Quidditch Cup riot, Harry searches his pockets for his wand, but doesn't find it — "The only thing he could find was his Omniculars". There's no mention of the leprechaun gold that Ron gave him, hinting that the stuff eventually disappears on its own.
• In the aftermath of the riot, Percy casually says he thinks it was unwise for Arthur to make a public statement that Rita Skeeter twisted into an article to make the Ministry look bad. In the next book, we learn that during their argument that led to Percy disowning the family, Percy told Arthur that he's a lousy employee with no ambition whose poor reputation he's had to fight against since starting his job there.
  • Similarly, after Sirius gives the Trio the rundown on the Crouch Family's backstory, Ron wonders if Percy knows all this ugly history. He concludes that even if Percy does, he'd approve of Crouch Sr. choosing the rules over his own flesh and blood. When Hermione protests Percy would never throw the Weasleys under the bus, Ron disagrees; he knows his older brother's ambitious enough that if he felt the Weasleys were doing anything to endanger his career, Percy just might do it. Ron's predictions are right on the money, as this very scenario will come to pass during the interim between Goblet and Order of the Phoenix.
• Voldemort's warning to Wormtail when he gives him the silver hand: "May your loyalty never waver again."
• Dumbledore gets "an odd look of triumph" after learning that Harry's blood was used in Voldemort's resurrection spell. It's not until very late in Book 7 that this pays off.
• When Moody shows Harry his collections, he specifically mentions he had to disable his Sneakoscope because it won't stop ringing. We immediately assume it's because it's malfunctioning or that Hogwarts is full of troublemakers, when it's actually going off because he's Barty Crouch Jr..
• While Harry, Ron, and Hermione confront Fred and George in the Owlery about their "blackmail" conversation over Ludo Bagman scamming them at the World Cup, George says to Ron: "Carry on like this and you'll be made a prefect." In Book 5, Ron is made a prefect alongside Hermione.
• At the Yule Ball, Percy says Rita is always "buzzing about," foreshadowing the fact that she's an unregistered beetle animagus.
  • Speaking of Rita, a beetle is mentioned as being on the scene during Hagrid's confession to Madame Maxime and Krum's conversation with Hermione after the second task. Yep, it turns out that beetle is actually her.
• Hermione's championing of house-elf rights is mostly treated with scorn and annoyance and nobody takes her cause seriously. The next book, Kreacher's casual mistreatment by everyone in No. 12 Grimmauld Place causes him to betray the Order, leading to Sirius' death. Hermione cites this as a cautionary tale, and when Harry starts showing Kreacher courtesy in Book 7, while also making him suffer a Heel Realization, he becomes instrumental in the fight against Voldemort.
• Moody covers for Harry when he's nearly caught out of bed and they even joke about "taking the egg for a walk." In the previous book, Lupin chided Harry for breaking the rules even after covering for him against Snape, saying he shouldn't be sneaking out when a mass-murderer is on the loose. The first hint that Barty Crouch Jr. doesn't actually care about Harry's safety.
• Likewise, Moody politely asks Harry if he can borrow the Marauder's Map, and Harry is so relieved to not be in trouble for being out past curfew that he agrees. Technically, Lupin had the authority to confiscate the Map on knowing what it was and did so after Snape nearly busted Harry. Thus, Moody could have simply confiscated the Map on the grounds that it was too powerful for Harry to have or such. Crouch Jr. admitted under Veritaserum that he was freaked out that the Map revealed his true name, so he was uncharacteristically nervous.
• Mad-Eye Moody tells Harry, "If there's one thing I hate, it's a Death Eater who walked free." Pays off when it's discovered that it's not really Mad-Eye Moody, but a loyal Death Eater in disguise as Moody who said it. He even explains that the reason he hates Death Eaters who walked free is not because he's an Auror and they managed to duck punishment (even though that would be a likely sentiment of the real Moody), but because in order to duck punishment, they deserted Voldemort the instant he 'died', lied about never knowing him, and didn't even try to bring him back, while Death Eaters like Crouch Jr. who remained loyal and attempted to bring him back instead of deserting to save their own skins got sent to Azkaban.
• Just before the climax, Voldemort tells his Death Eaters that he has gone further than anybody along the path that leads to immortality. We won't learn until Book 6 that he's talking about his Horcruxes and that he's done what no other Dark Wizard has done in recorded history: create multiple Horcruxes.
• Early on, Amos Diggory says offhandedly that a family known as "the Lovegoods" live not too far from the Weasleys. Luna Lovegood is introduced as a character in Book 5, and her family's house, which is fairly near the Burrow, appears in Book 7.
  • In one of the chapters Amos asks Arthur if all the kids are his. Turns out they will be in the future (as in laws).
• As Harry looks at the tent, the narration notes that he had never been camping before. Oh, will he become experienced in three years' time...
• During the Yule Ball, Dumbledore tells a story about stumbling across a bathroom that he was never able to find again. This seems like just an amusing anecdote at first, but in Book 5, it's revealed he used the Room of Requirement.
• Also during the Yule Ball, Moody catches sight of Harry's odd socks, which Harry specifically mentions were a gift from Dobby. Later on, it turns out this was useful to Crouch Jr. in getting the gillyweed to Harry. He made sure to summon Dobby and have a loud conversation about gillyweed with McGonagall. Since he knew Dobby was friends with Harry, Crouch Jr. assumed Dobby would do anything to help him.
• Hagrid mentions that Rita Skeeter wasn't happy with his favorable report about Harry. Ron jokes that she wants a new angle — "You were supposed to say Harry's a mad delinquent." By the end of the book, Rita does exactly that, laying the groundwork for a year-long Ministry smear campaign.
  • In the same vein, Dumbledore warns at the end of the year that "Lord Voldemort's gift for spreading discord and enmity is very great." The next year, the Ministry's refusal to accept that he's back creates a great deal of discord and enmity, the most notable example being between Percy and his family.
• The trio ponders how Rita could be getting her information while grinding up beetles for Potions. Rita turns out to be a beetle Animagus.
• Angelina is old enough to put her name into the Goblet of Fire, although she isn't selected. In Book 5, she becomes Captain of Harry's Quidditch team, presumably chosen because she's the oldest team member after Oliver Wood's departure.^note Or perhaps because she has the most seniority on the team — not to be confused with age — or else she's considered the best player still there. This would explain why Harry becomes Captain after Angelina leaves in Book 6 even though Katie Bell is a year older.
• Ginny is more talkative around Harry here than she was in Book 3, but only in the presence of other people. In Book 5, she can hold full conversations with him even when they're alone together (and Harry himself takes note of it), and then in Book 6, when Harry breaks up with her, she tells him that Hermione advised her that he would finally take notice of her if she relaxed around him, was more herself around him, and even dated other people to try to move on from him.
  • During the Quidditch World Cup, Ginny is very into the match and is horrified at Krum injuring the Irish Seeker. In Book 5, she replaces Harry as Gryffindor's Seeker after Umbridge bans him, Fred, and George from the team, and later Hermione tells Fred and George that Ginny has been breaking into the Weasleys' broom shed and teaching herself how to fly by taking each of their brooms out in turn when they weren't looking since she was six years old.
• During the first DADA class, Neville offers up information about the Cruciatus Curse (which Harry notes is odd, as Neville never offers up information in any class aside from Herbology) and is quite shaken after Moody demonstrates it on a spider. Many chapters later, we learn that his parents were tortured into insanity by a group of Voldemort's supporters using that curse and that's why he lives with his grandmother. For extra irony, Crouch Jr. is one of the very group of Voldemort's supporters who did that, at least according to the charges that Crouch Sr. brought up during their trial.
• Snape thinks someone is stealing ingredients from him to make Polyjuice potion and suspects Harry, who actually had played a part in stealing ingredients back in Year 2, which is what Harry thinks Snape is referring to here. He's not talking about the Year 2 theft. Someone is currently brewing Polyjuice potion, but it's Barty Crouch Jr, who is using it to pose as Mad Eye Moody.
• While looking at the Marauder's Map, Harry notices Barty Crouch going into Snape's office and wonders why the AWOL Ministry of Magic official would be wandering around Hogwarts late at night. It's actually Barty Crouch Junior, said Ministry of Magic Official's Death Eater son, who is secretly posing as Mad Eye Moody and is rummaging around in Snape's office for the Polyjuice ingredients that Snape was missing earlier.
• When Snape accuses Harry of stealing from his stores, he says, "Boomslang skin. Gillyweed." Harry immediately thinks of Hermione stealing ingredients for Polyjuice Potion back in his second year... but readers might remember that Hermione also stole bicorn horn, which Snape doesn't mention. Snape isn't referring to ingredients stolen two years ago, he's referring to ingredients stolen this year, by Crouch Jr. Not to mention that Harry and Ron had already explained that they had "borrowed" the ingredients, and Minerva adds it to their list of rulebreaking.
• During the Quidditch World Cup riot, as the trio are searching for Harry's wand, Winky darts across their path in an odd manner, "as though someone invisible were trying to hold her back". Namely, Barty Crouch Jr. who is under an Invisibility Cloak.
• The empty box seat that Winky is reserving for Mr. Crouch at the World Cup turns out to be where Barty Crouch Jr. is sitting.
• During the beginning of the final task, Harry feels really on edge as the he hadn't run into anything to block his way despite having been in the maze for a while. He feels like it's the maze trying to put him off guard but really it's due to Mad Eye Moody, or rather Barty Crouch Jr., removing all of the serious obstacles from Harry's path so he'll reach the end of the maze faster than the others.
• There is a ton of hidden stuff going on in "The Madness of Mr. Crouch" that we learn about from Barty Crouch Jr. at the end of the book.
  • For example, the "eagle" owl that is seen flying through the sky is actually an owl being sent from Voldemort. It's likely that he is letting Crouch Jr. know about his father escaping the Imperius Curse with possible instructions to kill him.
  • The pile of dirt that Hagrid is digging for the Nifflers is where Crouch Jr. will hide his father's body, transfigured as a bone
• At the Quidditch Cup Mr Weasley mentions a colleague called Bode who works as an Unspeakable in the Department of Mysteries, which plays an important part in the very next book.
• Harry and Malfoy get into a fight before Potions class one day and they happen to perfectly cast their spells at the same time, which collide in mid-air and bounce off each other. The climax of the story has Harry get into a similar fight with Voldemort and their spells collide in mid-air, this time causing a Beam-O-War because their wands are "brothers."

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