Fantastic Beasts: The Crimes of Grindelwald brought some titanic changes to the Harry Potter canon, reaching beyond the still-fledging Fantastic Beasts prequel series to flesh out events glossed over in the book series. And it doesn’t just affect the past. More so than the first Fantastic Beasts film, Crimes leaves plenty of dangling loose threads and where-to-go-next questions. Given that there are still three movies left in this saga, those loose threads likely won’t get tied up for years. (Pending a tweet from author / screenwriter J.K. Rowling that suddenly retcons everything, anyway.) But for now, here are the biggest puzzles facing fans who’re waiting for the third film.

Spoilers ahead for both Fantastic Beasts movies and the Harry Potter book series.

Who will carry on the Lestrange line?

Le-stranger things have happened

One big focus in Crimes is the Lestrange family, known from Rowling’s books because of Rodolphus and Bellatrix Lestrange, two of Voldemort’s most loyal Death Eaters. (And by extension, two pretty terrible people.) Crimes reveals that the Lestrange family has some extremely dark history to go along with their evil descendants, involving magical kidnapping, rape, multiple deaths during childbirth, and a selfish, fatal choice aboard a sinking ship that may or may not have been the Titanic. Crimes establishes a previous generation of the family, then promptly wipes it out. Between the deaths of the younger Corvus V and his half-sister Leta Lestrange, it’s not clear that there are actually any Lestranges left to carry on the name. The Lestrange family tree is complicated, but at the moment, the branches seem to have been pruned back pretty sharply.

Then again, it’s Harry Potter, and mysterious lost relatives are constantly turning up out of the blue. Le-stranger things have happened.

How does the timeline work now?

The Crimes of Grindelwald doesn’t just introduce new faces to the Potter world — it brings back some old friends in young forms that don’t really make a ton of sense.

Chief among those is the appearance by a young Professor McGonagall, whose brief scenes in Crimes of Grindelwald don’t fit the franchise’s established timeline. McGonagall’s birthday had previously been worked out by fans at the Harry Potter wiki to be in 1935, eight years after Crimes takes place. McGonagall herself notes in Order of the Phoenix that she had only been teaching at Hogwarts for “thirty-nine years this December” in 1995, putting her start date in 1956. And yet Crimes has her as an adult, already teaching at the school in 1927. The obvious answer is that the “Professor McGonagall” in the film is an older relative — again, Rowling loves to bring in recognizable names from different generations — except that the film’s credits and Rowling’s official script both indicate that the character in the film is Minerva McGonagall. That’s confusing, but it’s unlikely to be a mistake — it’s more likely that Rowling is changing the timeline somehow.

What happens to Nagini?

Another one of Crimes’ canon bombshells is the appearance of Nagini — known from the books as Voldemort’s giant snake, which swallows victims whole and poisons Arthur Weasley with a nearly fatal bite. But here, she’s revealed as a “Maledictus,” someone suffering from a magical blood curse that will eventually cause her to permanently turn into a snake. (And a particularly long-lived snake at that, given that she’s still around in 1998, when Neville Longbottom beheads her in Harry Potter and the Deathly Hallows.)

In 1927, though, she seems like a comparatively sympathetic woman, who bonds with Fantastic Beasts’ living MacGuffin Credence Barebone, becoming his only obvious friend until Grindelwald lures him away. Credence is possessed by a dark destructive force known as an Obscurus, which Grindelwald hopes to use as a weapon against his nemesis, Albus Dumbledore. But the dark wizard leader doesn’t seem to have any particular use for Nagini, and she gets left behind. She doesn’t have much to do in Crimes at all, besides shouting ineffectual protests as Credence makes poor decisions. Presumably her journey from the woman we know now to one of Voldemort’s soul-containing Horcruxes will factor into the next few films.

Is Credence really who Grindelwald claims he is?

Crimes’ biggest twist is saved for its final moments, when Grindelwald reveals Credence’s supposed true identity. He apparently isn’t a random orphan: he’s Aurelius Dumbledore, the lost scion of the Dumbledore family and alleged brother to Albus and his siblings, Aberforth and Ariana. That reveal has staggering implications for the Potter world, given that it seems almost impossible that Dumbledore had a secret, lost younger brother, considering the timing.

To briefly recap the history of the Dumbledore family, as detailed in various interludes in Harry Potter and the Deathly Hallows: previously established history reveals that Dumbledore’s father, Percival Dumbledore, was sent to Azkaban sometime around 1890, after attacking three Muggles who traumatized and attacked his six-year-old daughter Ariana. Percival is then said to have lived out the rest of his life in prison, although it’s unclear how long that was.

That reveal has staggering implications for the Potter world — if its true

Dumbledore’s mother, Kendra Dumbledore, took care of Ariana on her own as best she could, even though Ariana was unable to control her magic after her assault. (Many fans speculate that the trauma may have left her with her own powerful, dangerous Obscurus, like the one inhabiting Credence.) When Ariana was 14, a magical accident — or Obscurus outburst — caused an explosion that killed Kendra, leaving Albus stuck at home as her caretaker at roughly age 17. That was when Albus met Grindelwald.

Over that summer, Albus and Grindelwald grew close. Albus wanted to travel the world with his new friend, but his brother Aberforth was concerned over Ariana’s health. A three-way duel between Albus, Aberforth, and Grindelwald resulted in an accident that left Ariana dead.

With that timeline established, it’s difficult to figure out where on earth Credence / Aurelius fits in. Rowling’s Crimes of Grindelwald script indicates he was an infant on a boat to America in 1901. So it’s hard to understand how he would have been born as a full brother to Albus, Aberforth, and Ariana — especially since in the films, he appears to be significantly younger than Albus.

So is Credence really a lost Dumbledore? Grindelwald could simply be lying to Credence about his heritage. (He’s a monumentally manipulative villain, after all.) Credence could be a cousin or relative from some other branch of the family. And there are theories that Ariana — assuming she was possessed by an Obscurus — somehow transferred part of her soul when she died, which ended up in Credence somehow, making him a more metaphorical brother. That’s less ridiculous than it sounds — Voldemort accidentally does something similar to Harry Potter while attempting to kill him.

That’s all assuming that J.K. Rowling just doesn’t have a larger retcon planned — it wouldn’t be the first time she’s changed a major character’s history. In fact, it wouldn’t even be the first time in this movie, given the changes to Nagini’s character in the film.

What happens to Grindelwald and Dumbledore?

As noted last time around, we do already sort of know where this is all heading: in 1945, Dumbledore and Grindelwald reunite, with the two powerful wizards facing off in what Rowling describes in the Harry Potter books as the “greatest wizarding duel of all time.” But Crimes adds a few new wrinkles to that eventual fight.

Specifically, there’s more context about why it takes Dumbledore so long to rouse himself to fight his former friend / lover (a relationship Rowling and the films remain frustratingly coy in establishing on-screen). Apparently, the two wizards once swore a “blood pact” against battling against each other, taking the form of a pendant that contains droplets of both their blood. Until that pact is broken — Dumbledore suggests at the end of Crimes that it’s possible, since he ends up with the pendant in hand — the wizarding world’s most powerful ally has his hands tied when it comes to confronting the threat.

Crimes adds a few new wrinkles to that eventual fight

We also get more information as to how Grindelwald is getting the Wizarding World on board with his agenda — visions of the horrors of the future World War II, something that rings as tone-deaf, given that Grindelwald’s movement is expressly designed as an emulation of the Nazi regime. (The rabid followers, time period, message of racial superiority, adopted insignia used to represent a hateful movement, and the prison with an insidious motto carved above the gates are all giveaways here.)

Given that The Crimes of Grindelwald takes place in 1927, that leaves a gap of 18 years during which Grindelwald can put his plans into motion. We do know that his reign of terror left a scar on the international wizarding community — as Victor Krum relates to Harry Potter in Deathly Hallows, “Grindelwald killed many people, my grandfather, for instance. Of course, he was never powerful in this country, they said he feared Dumbledore.” Grindelwald’s mark — the sign of the Deathly Hallows — also went on to carry a distinct taboo, with Krum noting that he and other fellow students who had family members killed during Grindelwald’s crusade clashed with classmates who wore the sign when he was at school.

As for Grindelwald himself, we already know his end, too — after the duel, he’s imprisoned in his own Austrian fortress of Nurmengard (“the prison Grindelwald had built to hold his opponents”), and later killed by Lord Voldemort in pursuit of the Elder Wand. It’s a longstanding problem with prequels — knowing where so many of these subplots will end makes it harder to find them engaging and mysterious. But Rowling’s still leaving some big mysteries open, with three films left to explore them.