Warning! A couple of spoilers for the new film lie ahead.

Alison Sudol watched fan-made YouTube videos to learn more about Legilimency

Alison Sudol had a full-on Harry Potter geek-out session when it came to researching her character of Queenie's power of Legilimency, the mind-reading skill also explored in the Harry Potter books.

‘Fans are so detailed in their love and appreciation for these stories,’ she said. ‘I actually researched more on Legilimency on Youtube through fans! And I was like, “Oh Snape had it too?’ ‘Oh, it’s much more powerful than I knew!” so there’s something really cool and exciting.’

And she was ‘so stressed out’ about finding out about Queenie’s character development

As anyone who has seen the new film will now know, Queenie’s story takes an unexpected twist.

‘I knew the arc, I knew what was going to happen at the end,’ she explained. ‘So I spent months going, “how? How does this happen? How am I going to go there?” and just so stressed out about it. But even when I read the script, I was still shocked.’

Likewise, Alison!

J.K. Rowling wrote pages of back-stories for the new characters

Fantastic Beasts: The Crimes of Grindelwald welcomes many new characters – and despite some of them being on screen for just a short time, Eddie Redmayne revealed that J.K. Rowling had fully fleshed out histories for them.

‘For example, Bunty, who is Newt’s assistant in the film, who is so lovely and is played by an actor named Victoria Yeates, only has one scene in this film,' he said.

'She and Newt clearly have a relationship and it’s quite a well-established relationship. So, Victoria and I asked Jo what their history was. The next day, three pages of original J.K. Rowling text, now kept in my safe, was written about the depths of their friendship and where it had come from and how Bunty had come to the book signing and had been obsessed with Newt.’

‘It would be an amazing party trick,’ Katherine Waterston added. 'If you could ever get J.K. Rowling to ever go to one of your parties — to be like, ‘What was third grade like for Tina?’ And Jo could say, ‘Oh well, that was a tough year. She was falling back in math.’ She knows everything, there’s not even a pause; it’s there at her finger tips. It’s uncanny.’

The cast just loved Jude Law as Dumbledore

‘He’s perfect. In my opinion - just the accent, the glint in his eye... the shape of his beard even,’ Dan Fogler said of their new co-star Jude Law.

‘He’s charming, he’s got a bit of that twinkle, and he’s got that pain,’ producer David Heyman added. ‘Dumbledore is a pained, tortured character. And you don’t always read that pain and suffering on the surface, but when you see him quietly in front of that mirror.... that’s Jude.’

And everyone was fascinated by Dumbledore’s nuanced relationship with Grindelwald

A lot has been discussed about Dumbledore’s younger days growing up with Gellert Grindelwald. In the new film, Dumbledore refers to their relationship as ‘closer than brothers’. David Heyman discussed the script’s subtle references to their past.

‘I think it’s pretty clear when Dumbledore says they were more than friends that it suggests an intimate relationship,’ he said.

‘We know. We feel it’, Callum Turner, who plays Theseus Scamander, added. ‘There’s a [John] Cassavetes quote that goes, ‘Art is not pictures – it’s feeling’ and you feel these films, you feel these characters.’

Eddie Redmayne concurred, noting the ‘extraordinary intimacy’ between the pair.

‘[Dumbledore] sees Grindelwald in the Mirror of Erised. You see extraordinary intimacy and love even in the brief moments that it’s exposed. I think that [Jo] is just telling a story over five films and we will see more of their relationship.’

Ezra Miller’s favourite beast is the horrible Lethifold

An inevitable question to ask the cast is what their favourite fantastic beast is – the second instalment introduces us to many newbies. But according to Eddie Redmayne, Ezra Miller’s favourite is a little more niche – the Lethifold.

According to the Fantastic Beasts and Where to Find Them textbook, a Lethifold is a carnivorous cloak-like creature that suffocates humans at night. Oh, Ezra.

Eddie Redmayne really enjoyed ‘licking a pavement’

An actor often faces many challenges throughout their career, and the Oscar-winning Eddie Redmayne certainly met a new one in this film when his character has to lick pavement. Of course, Eddie took it all in his stride.

‘It was great’, he laughs. ‘I wanted it to be like tasting a wine.’

The mysterious ship is most likely not the Titanic

In one scene in the film, we see a flashback sequence with Leta Lestrange traveling on a ship with her brother – with tragic results when the ship begins to sink. Many fans have wondered if this is the famous sinking of the Titanic, which happened in 1912. David Heyman, however, disputed this.

‘It was never discussed,’ he told us. Although Callum Turner cheekily added, ‘I bet it could have been.'

Mysterious!

Dan Fogler cried ‘at least three times’ reading the script

Emotions run high in this new fantastic offering, and Dan Fogler was honest when it came to his reaction to the script.

‘Oh my god, it’s really heartbreaking,’ he admitted. ‘I watched the movie twice, I cried twice, at least three times... and I was there!’

And Ezra Miller was ever-so-slightly surprised by the ending of the film

‘Yep, there was a period of shock,’ Ezra Miller says not-so-casually.

Those who have seen the film will know why...

Fantastic Beasts: The Crimes of Grindelwald is out in cinemas now.