In many of Harry Potter’s adventures, there’s a similar turning point: Halloween. And it’s not just the pumpkin juice and cauldron cakes that set it apart. Something often happens on Halloween itself that completely changes the rest of the school year at Hogwarts School of Witchcraft and Wizardry.

The significance of Halloween is evident in the majority of the Harry Potter books, and today Pottermore points out that significance, noting that in the first four Harry Potter books, something pivotal happens on Halloween.

In Harry Potter and the Sorcerer’s Stone, a harrowing run-in with a troll cements Harry, Ron, and Hermione’s friendship on Halloween. The Chamber of Secrets is reopened on Halloween in Harry Potter and the Chamber of Secrets. In Harry Potter and the Prisoner of Azkaban, Sirius Black sneaks into Hogwarts on Halloween and causes school-wide panic beginning with the Fat Lady. Harry was chosen as one of the Triwizard Champions on Halloween in Harry Potter and the Goblet of Fire. Outside of Hogwarts, the event that changes Harrys life and sets the stage for the entire place takes place on Halloween, when Voldemort kills Harry’s parents.

The Halloween Feast in 'Harry Potter and the Sorcerer's Stone'

The holiday arrives at the exact right moment to signal that we’ve no longer just arrived at Hogwarts — the year is beginning in earnest, and that means that the action is picking up. Without the events of not one or two but several Halloweens, the Harry Potter series would be unrecognizable. But what about the missing Halloweens? There’s no real fanfare or event for Halloween in the last three books, but when it comes to Harry Potter and the Deathly Hallows, Halloween is important for its absence more than its presence. Because there’s no important Halloween event, this is part of what sets a somber tone for this particular story.

In the final adventure, everything has changed, and Harry, Ron, and Hermione enjoy none of the familiar comforts of Hogwarts. Perhaps Halloween passing without recognition only seems fitting in fact, there’s no real recognition of holidays at all until Harry and Hermione visit Godric’s Hollow to discover that Christmas Eve has arrived without them realizing it.

As we approach Halloween and the release of Fantastic Beasts and Where to Find Them, we can’t help but wonder if Halloween might play an important role in the Potterverse stories to come, too.

Photos via Warner Bros Pictures, Warner Bros