The Harry Potter Fan Theory That Explains A Hogwarts Express Mystery

In a world as rich and dense as the Wizarding World created by J.K. Rowling, there are bound to be inconsistencies. And with a fan base as passionate as the one that surrounds Harry Potter and friends, every detail is picked over and theorized about until it makes sense. So, in the case of a particular Hogwarts Express mystery that had moviegoers saying, "Huh?", one fan theory on Reddit has an explanation that seems to work. 

It all starts in "Chapter 5: Diagon Alley" of Harry Potter and the Sorcerer's Stone, when Hagrid hands Harry an envelope he says has a ticket to the Hogwarts Express. The ticket isn't mentioned again as Harry finds his way to Platform 9 3/4 — with the help of Mrs. Weasley — and finds a seat on the train. The scene is in the movie as well, when Hagrid gives Harry his ticket to the Hogwarts Express and tells him it leaves in ten minutes. "Stick to it," he says in the first flick, "It's very important. Stick to your ticket." There's even a close-up of the small piece of paper that's designed to get him aboard the train. And that's all.

But why is there so much stress on this ticket that never seems to make another appearance? It's not like the train was going to turn away any of the young wizards headed for school: Chances are, there's a list somewhere, and this is no random passenger locomotive for the general public. And this is Harry Potter, after all. He's famous, a household name for wizards. Would Harry would ever be turned away by an overzealous train conductor?

The easy answer, of course, may be that this is early days in Harry Potter, and the scene ends up being a throwaway world-building moment that isn't needed or wanted and doesn't come back. But one fan, expounding on Reddit, has come up with a theory that seems just as legit as any other possibility. 

A user posted the theory to Reddit early in 2021, saying, "So here's my theory: the ticket actually holds the Fidelius charm, just like the piece of parchment Harry received from Mad Eye in book 5, revealing Grimauld Place 5 [sic]. It explains why muggles don't notice hundreds of children running through a wall in an immensely crowded place, and why they never receive a ticket again after their first year, since they only need to find out about the place once."

As you may recall, the Fidelius Charm is described by Professor Flitwick in Harry Potter and the Prisoner of Azkaban as "an immensely complex spell" in which the secret is kept inside one person. Only the person who knows the secret, called the Secret-Keeper, can tell others. The Secret-Keeper can do this in writing, as Dumbledore did to Harry with regard to 12 Grimmauld Place in Harry Potter and the Order of the Phoenix, and once the Secret-Keeper dies, the others who know the secret all become Secret-Keepers. As with many things in the wizarding world, the Fidelius Charm gets more complicated the more you think about it. 

Now, with Grimmauld Place, only the Order of the Phoenix was allowed inside. In the case of the Hogwarts Express, the Fidelius Charm would basically be expanded to every family who had children that qualified to go to Hogwarts, basically only keeping muggles away. In the series, when events or places (like Hogwarts itself or the quidditch pitch where the World Cup was held) have needed to be hidden from muggles, there are other, better enchantments designed for that purpose. But this theory still makes some sense!

As with any fan theory — or any post on Reddit — people quickly started to analyze and try to poke holes in the original assertion. One pointed out that there didn't seem to be any restrictions about talking about Platform 9 3/4, as Harry did when explaining to his aunt and uncle where he was supposed to meet his train. Others weren't certain what sort of talk was actually covered by the Fidelius charm or how much information might have to be revealed for the Fidelius charm to work properly.

Another theorist pointed out that the ticket might be for the muggles' use. Perhaps Harry's Uncle Vernon wouldn't have taken him to the train at all without proof that it existed and that his troublesome nephew might actually be spirited away for most of the year. Others agreed that the ticket might be more for the comfort and information of families who were sending their kids to Hogwarts for the first time, or an anti-anti-muggle-repelling charm to allow parents to bring their children inside. 

Poster @jonathanquirk thought that if it was the Fidelius charm, there'd be no need to hide Platform 9 3/4 behind a wall. "But the ticket might still be charmed in some way, an invite that means only authorised travellers are allowed on the Hogwarts Express," the user noted. Others also thought a different spell could be being used here, as another Redditor pointed out. For example, the physical ticket might open up a portal of some kind, or it could be some sort of tracking method.

This is one of those topics that, to fans, requires lots of text-searching and consideration to come to a reasonable conclusion. But one thing is clear: Ultimately, there's only so much logic that can be applied to the situation. This is magic, after all.