Cate Blanchett on The House with a Clock in Its Walls: 'I loved playing a witch'

Cate Blanchett in The House with a Clock in its Walls. Photo / supplied

With its mix of magic and mystery, The House with a Clock in its Walls - the first in the series of books by John Bellairs – has been compared to another master of magic, Harry Potter. Is it all an illusion?

"Doing this film was the happiest I've ever been on set," says Cate Blanchett, flashing her familiar cat-got-the-cream smile, as she animatedly chats about her bewitching role as Florence Zimmerman, in the kids' fantasy The House With a Clock in Its Walls.

It's a surprising admission, given Blanchett's penchant for dramatic, weighty film roles, beguiling theatre performances and her triumphant, Oscar-winning portrayals in The Aviator and Blue Jasmine.

"I loved playing a witch and loved doing this film because magic makes me scream," she reveals, her eyes widening with unbridled excitement. "I have a cousin, who's ten years older than me, and he's also obsessed with magic. When I was a kid, we used to go to his family's farm and we'd lock him in a room and make him perform magic for us. It was just stupid things, like pretending to take your nose off or cutting a lemon and out comes the card that you've picked, but I adored it.

"So, I was thrilled by the prospect of working on a film full of magic, based on a book that I'd known – and loved - from my childhood," continues Blanchett, passionately. "I found the whole experience enthralling."

"It was the same for me," adds Jack Black, who co-stars with Blanchett as her madcap, mystical Warlock neighbour, Jonathan Barnavelt. "I like to do films that I have an opportunity to flex my muscles in, so getting the chance to play someone with magical powers and create an invisible energy ball, right in my hand, was a fun first. It was a great experience, one of the funniest films I've ever done."

Cate Blanchett and Jack Black in The House with a Clock in its Walls. Photo / supplied

That's apparent during Black and Blanchett's paired interview, with the two of them continuing their on-screen banter off-screen, as they playfully tease each other and joyfully swap anecdotes. It's clear their fantasy pairing on camera has blossomed into a real-life friendship.

In fact, watching Blanchett as she jests with and jibes Black is a revelation – and far removed from the demure, Hollywood superstar she's often depicted as. But it mirrors her playful performance alongside him in The House with a Clock in its Walls, especially a key, magical scene where the two tease and taunt each other mercilessly with mock insults, sparring like long-suffering real-life partners.

"That scene was so funny. It was such a hoot to do," says Blanchett, unconsciously whooping with glee. "Some of those exchanges were straight from the book, some were scripted, but we also threw in a few of the lewd ones ourselves. That made it even more spontaneous and fun."

Accordingly, The House With a Clock in its Walls is full of spellbinding fun, frivolity, magic, mayhem, and mysticism. But there's also a darker underbelly of death, deceit and doomsday underpinning it, with harrowing horror scenes ensuring it's far more sinister and scary than most kids' flicks.

"It is dark and dangerous, especially for a children's book, but what else would you expect from a director like Eli Roth, who's made some pretty hardcore horror films," asserts Blanchett. "Actually, that's another reason why I wanted to do this film, because I'm a huge fan of horror.

"I love horror and adore murder mysteries. I had a big obsession – I still do – with gore, although I do find it harder to watch, now that I have children," she says. "Maybe it's something to do with giving birth?"

Cate Blanchett, Owen Vaccaro and Jack Black. Photo / AP

Speaking of which, what do her kids think of her starring in a fantasy franchise that's being likened to Harry Potter? Was that one of the appeals of doing The House With a Clock in its Walls?

"I don't really think it is like Harry Potter," she says. "Sure, you've got people with weird, magical powers but they live in the real world, not some faraway, fantasy place, so there's quite a different relationship with the world you find in Harry Potter.

"As for my kids, they couldn't care less about me being in this, or anything else. They just find it creepy seeing me in movies and hate watching me on stage," she says. "Maybe they secretly watch my films but I think, to them, I'm just this really uncool, embarrassing mother who says things like 'invite your friends round and we can have some roast lamb...' or 'let's make a chocolate mousse together'. To be honest, I just feel like a failure most of the time, like any other mother of teenage kids does.

"You know, a lot of actors will say; 'Oh, I just want to do this for my kids...' but they don't; they're just pretending because really they want to work with a certain director, or do a Marvel movie. I'm the same," says Blanchett. "I may pretend I'm doing it for my kids but the reality is I selfishly do things that interest me.

"In fact, the influence the children have on my work is fairly minimal. About the only way they do impact it is logistically, because with four children sometimes I can't physically do something I'd love to do because it doesn't fit into my everyday life."

That may very well change, with The House with a Clock in its Walls already striking a chord with young and old alike – especially as there are still nine other books in the series.

It means Blanchett's kids may just have to get used to seeing their mum over and over again, in what might become the potential hit successor to the Harry Potter franchise.