Two and a half weeks after the release of Fantastic Beasts and Where to Find Them, fans have blown wide open a theory about two important characters from the wizarding world.
In a post on Reddit, user Janu567 reveals a possible reason as to why Hogwarts headmaster Albus Dumbledore’s sister, Ariana, is rarely talked about in the Harry Potter series.
And it’s because, according to Janu567 at least, Ariana was an obscurial.

Image via Warner Bros.
Like Credence in Fantastic Beasts and Where to Find Them, an obscurial is a magical parasite that develops when a wizard or witch doesn't use their powers or tries to hide their true self from those around them. But the more a witch or wizard tries to suppress their magical ability, the more likely their magic is to destroy them.
As readers of J.K Rowling's best-selling books will remember, Ariana Dumbledore's death was caused by a fight with her mother.
But despite being the sister of one of the world's greatest wizards, her presence isn't known until Harry Potter and the Deathly Hallows - the final installation in the seven-part series. And even then, she is only mentioned twice - once in an obituary, and then again at the end of the series when Harry meets Aberforth, Dumbledore's brother.
"She wouldn't do magic, but she couldn't get rid of it; it turned inward and drove her mad, it exploded out of her when she couldn't control it..." Aberforth told Harry in the movie.
And so enters janu567's theory, which goes like this: after an incident involving muggles, Ariana tried to bury her magical ability. But instead, her power turned inward and she would explode just like Credence does.

Top Comments
THAT'S NOT A THEORY. Doesn't anybody read the books anymore? It's clearly stated there! Ariana was attacked by a group of Muggle boys when they saw her doing magic when she was young, and so she avoided doing it ever since. But because she was young, she couldn't always control it.
I wish fans wouldn't just rely on the movies for their HP education. If the people involved in this discussion had just read the relevant book, this wouldn't have been discussed as a "theory" at all!
As people below have already said, Ariana wasn't killed in the fight with her mother. She was killed in the crossfire during the fight with Albus, Grindelwald and Aberforth.
I do agree that it sounds likes she was an obscurial.
Maybe a rereading of the final book is in order!
The book clearly describes her as an obscurial. It's not a fan theory at all - it's stated in the books (without using the term), and even has a backstory about Ariana being attacked by Muggle boys when they saw her doing magic when she was young.
Yeah, definitely. I still haven't seen the movie, but from the description given as to what an obscurial is, it's clear that Ariana was one of them
I suspect it's probably J.K. Rowling going back over what she'd written, attaching a term to it and making it a "thing" (or perhaps she had always intended it to be a "thing"!). It just annoys me that this theory has been based off the movies; people never return to the original source material. It's not even confined to fan theories, either - I got really excited when I saw a HP Trivial Pursuit game the other day, until I realised it was based entirely off the movies, and not the books. Reviews say it means there are often conflicting answers. The books are the originals - they should be the base!
Yeah, regarding Trivial Pursuit, that would annoy the hell out of me!