The Darkest Harry Potter Mystery Still Unsolved — And Why the Reboot Solving It Would Break the Biggest Rule

Seven books. Eight films. A vault of secrets. From Snape’s true allegiance and the Half-Blood Prince twist to R.A.B.’s identity, why Harry survived the killing curse, and how Voldemort returned, we break down the reveals that rewired the saga.

Harry Potter solved a mountain of riddles over seven books and eight movies, and then J.K. Rowling kept answering even more in interviews and on Pottermore. And yet, somehow, the franchise still leaves one of its darkest questions sealed up like a cursed locket: how do you actually make a Horcrux?

Wait, didn’t Rowling already explain everything?

To be fair, a lot did get cleared up. We found out where Severus Snape’s loyalty really was (and that he was the Half-Blood Prince), who R.A.B. turned out to be, how Harry survived Voldemort’s killing curse, and how the Dark Lord clawed his way back. After the books, Rowling kept filling in blanks we did or didn’t ask for — from confirming that Albus Dumbledore is gay and once in love with Gellert Grindelwald to, yes, how wizards deal with bathroom logistics.

But some things never got real answers. The Veil in the Department of Mysteries? Still a mystery. Harry’s extended family? Mostly foggy. And the big one: the mechanics of creating a Horcrux.

The question the story hinges on

We know the basic rule: you commit murder to split the soul. Beyond that, Rowling has never laid out the exact steps. In a 2007 PotterCast interview, she even said there are lines she won’t cross on the record. This is one of the very few times she essentially shut the door on canon detail:

"I see it as a series of things you would have to do. So you would have to perform a spell. But you would also - I don't even know if I want to say it out loud, I know that sounds funny. But I did really think it through. There are two things that I think are too horrible, actually, to go into detail about. One of them is how Pettigrew brought Voldemort back into a rudimentary body. 'Cause I told my editor what I thought happened there, and she looked as though she was gonna vomit. And then - and the other thing is, how you make a Horcrux. And I don't even like - I don't know. Will it be in the Encyclopedia? I don't know if I can bring myself to, ummm... I don't know."

So what could be that awful?

Fans have been workshopping theories for years, and some of them get very grim. A few of the most-discussed ideas — and why they do or don’t line up with what we know:

• Cannibalism: The brutal version says the killer consumes part of the victim to bind the soul fragment. It’s certainly horrific enough, but it clashes with canon details. When Tom Riddle killed his parents — around the time he began making Horcruxes — their bodies showed no signs of injury or illness, which makes this tough to square.
• Self-mutilation alongside murder: Another theory argues you have to harm yourself in a severe, ritualistic way as part of the process, which could help explain Voldemort’s increasingly inhuman look. This one doesn’t contradict anything outright, but there’s no direct proof.
• Consuming part of the victim’s soul: A twist on the cannibalism idea that shifts from flesh to something metaphysical — the killer ritually takes in a piece of the victim’s very essence. It fits the vibes, even if it’s more poetic than provable.

The satisfying non-answer

Honestly, this feels engineered to stay unknowable. Rowling has said she worked it out, but the specifics either don’t exist in a way that can land on the page, or they’re so grotesque that spelling them out would be a net loss. And that’s probably for the best. The Horcruxes work because they’re terrifying, not because we can diagram the ritual.

Even with a new Harry Potter series in the works at HBO/Max that’s set to go deeper into the books, I wouldn’t expect a step-by-step Horcrux manual. Some corners of this world just play better in shadow — a note that might’ve helped with a few lore over-explanations elsewhere.

If you’re in a rewatch mood

The films stream on Max, and the upcoming HBO/Max series aims to expand the books. Just don’t hold your breath for a definitive Horcrux recipe. Sometimes the darkest magic is scarier when we’re left to connect the dots.