Warning: This post contains theories and potential spoilers for Fantastic Beasts: The Crimes of Grindelwald.

With only a month until its premiere, promotion for Fantastic Beasts: The Crimes of Grindelwald has shifted its focus to Ezra Miller’s Obscurial Credence Barebone, arguably the most dangerous wizard alive. In a new teaser about how everyone in the movie travels to Paris to find him, Credence says, “I want to know who I am.” The question of who Credence is and where he comes from might be the single most important one of the entire franchise. And we think we know the answer.

Entertainment Weekly and Pottermore revealed William Nadylam’s Yusuf Kama—a “French-African wizard who claims to be the last male member of his pure-blood family line” who has only appeared briefly in the trailers—swore an Unbreakable Vow to find Credence. It should be noted that Yusuf and Leta Lestrange are half-siblings with the same mother; Leta’s father is an “evil wizard” named Corvus Lestrange, who is said to have “taken” Yusuf’s mother Laurena. The evidence that orphan Credence is also the son of the apparently amoral Corvus is far from circumstantial. A shot from an earlier trailer shows Dumbledore looking at a glowing family tree of Corvus, with Leta being his daughter with his first spouse Laurena Kama, and Credence being his son with a witch with the very French-sounding name Clarisse Tremblay.

This likely half-sibling relationship between Leta, who is currently engaged to Newt’s brother Theseus, and Credence introduces new reasons to worry that Credence may wind up siding with Grindelwald. First, as a Lestrange it’s hard to trust that Leta won’t join Grindelwald, especially since we know he is holding his rallies in the Lestrange Family Mausoleum. If she joins the Dark Wizard, that could make her newly-found half-brother, the outsider desperate to belong somewhere, join with her. Add that to the fear that Nagini may do the same if Grindelwald promises to cure her blood curse, which he might have also shared?

But the biggest concern of all—as voiced by Dumbledore in this latest promo, when he says, “Credence might not know who he is yet, but he needs to be found.”—is that the evil wizard Corvus Lestrange was Grindelwald in disguise all along, and both Leta and Credence are his children.

We know from watching him assume Percival Graves’ identity Grindelwald can pull off a massive identity deception. He also used his sexuality to manipulate Credence in the first film, something he might have also done years earlier as a teenager with Dumbledore. And for someone obsessed with wizard supremacy, he would have wanted offspring with pure blood witches to create his own heirs.

So what might have happened to Credence? The wizarding world is small. If Laurena knew the truth about “Corvus,” it’s possible she knew about his other child with Clarisse, who hid her son in America to keep him away from Grindelwald. Grindelwald may have found out and gone to America to find his child who was hidden among the No-Majs away from magic (resulting in an Obscurus), but may have wrongly thought he was on the hunt for Leta. Along the way, he learned the truth about Credence: that he was the most powerful weapon in the world, and also his son.

“The path has been laid, and he is following it, the trail that will lead him to me,” Grindelwald says about Credence. But Dumbledore has Newt trying to find him before he gets there, and so is Yusuf… unless that is Yusuf wants to bring him to Grindelwald. No one can be trusted.

The film’s tagline is “The fate of one. The future of all.” The one certainly appears to be Credence, whose father might very well be Grindelwald. If Credence is fated to join his family that could determine the future for everyone.

What do you think? Is Grindelwald really Corvus Graves, the father of Leta and Credence? Tell us if you’re casting doubts on this theory, or if you think we mixed the right potion.

Images: Warner Bros