As most fans of the series already know, the Harry Potter books are filled to the brim with subtle, clever moments of foreshadowing. To some, these references to future events and places only became clear and obvious as the story went on. But, those moments of foreshadowing in the Harry Potter books don't just come in the form of building up to Harry's eventual fight with Voldemort at the end of the series, or the growing romantic tension between Ron and Hermione.
In fact, the books are littered with hidden messages and details, most of which slyly set up tragic character deaths in the series' later installments, or the incipient introduction of major places, objects, and characters. While some of these Harry Potter foreshadowing moments managed to make their way into the film adaptations too, it shouldn't be surprising that most were left for the book readers to discuss amongst themselves.
So, in honor of author J.K. Rowling's hard and detail-oriented work writing the series, let's explore some of the best moments of foreshadowing in the Harry Potter books.
Barty Crouch Jr. actually saw Snape in his Foe-Glass near the end of The Goblet of Fire. This quickly, and subtly, revealed Snape's true allegiance in the conflict between Harry and Voldemort.
Book readers could be forgiven for missing this small moment of foreshadowing in the fourth book. After all, it happened amidst the chaos of Dumbledore and the other Hogwarts professors saving Harry from the machinations of the undercover Barty Crouch Jr. But it's a noteworthy moment all the same, since the first thing Snape did when he arrived in Crouch's Hogwarts office was to approach the Death Eater's Foe-Glass.
Remember, a Foe-Glass is a magical object that allows the owner to see their true enemies at all times. Snape appearing in the mirror at first seemed like a bad sign to Harry, since Crouch spends most of the book masquerading as the heroic Mad-Eye Moody. However, when it's later revealed to be Crouch's Foe-Glass and not Moody's, Snape's appearance is a smart and subtle way for Rowling to communicate to book readers that Snape was on Harry's side all along.
One of Professor Trelawney's many superstitions actually predicted the deaths of Albus Dumbledore, Sirius Black, and Remus Lupin. This foreboding moment came about halfway through Prisoner of Azkaban, when Dumbledore stood up and invited Trelawney to join him and his 11 other table guests at dinner in the Great Hall. The Divination professor refused his offer, saying: "If I join the table, we shall be 13! Nothing could be more unlucky! Never forget that when 13 dine together, the first to rise will be the first to die!"
This proved to be a tragic point of foreshadowing in the books. As it was later revealed in Prisoner of Azkaban, Ron had actually brought Scabbers with him to that dinner, meaning there were already 13 people at the table. Then Dumbledore stood up. This sort of foreshadowing happened two other times in the series, when both Lupin and Sirius were the first of 13 people to rise from a dinner table.
Harry and Ron mockingly, and unknowingly, predicted all three of the dangerous Triwizard Tournament tasks in Harry Potter and the Goblet of Fire, one whole year before the games take place.
This piece of foreshadowing was thrown out in a seemingly lighthearted fashion, when Harry and Ron grew tired of their endless amounts of Divination homework in Prisoner of Azkaban. Instead of actually trying to read tea leaves and predict the future, the duo decided to start just kind of... guess.
Harry's predictions included that he would be in danger of burns, lose a treasured possession, be stabbed in the back by a friend, and come off worse in a fight. All of these eventually came true in Goblet of Fire, when he had to fight a dragon, save Ron from dangerous underwater mermaids, and was betrayed by Barty Crouch Jr. masquerading as Mad-Eye Moody. And, of course, he barely made it out alive from his graveyard fight with Voldemort.
A brief interaction between Harry and Dumbledore at the end of Goblet of Fire directly set up one of the key components to Dumbledore's overall plan to stop Voldemort. At the end of Goblet of Fire, Harry spent several chapters completely exhausted, drifting in and out of lucidity.
So, when he told Dumbledore that Voldemort came back to life using Harry's own blood, Harry mentioned seeing a brief moment of triumph in Dumbledore's eyes. This left many book readers confused. After all, it seemed like a strange moment for Dumbledore to be feeling triumphant about anything.
However, Dumbledore's reaction actually set up the reveal in Deathly Hallows: that Voldemort using Harry's blood was what would kill the Dark Lord once and for all. It was, in fact, something Dumbledore secretly hoped Voldemort would do. A triumphant moment indeed.