Vanessa Kirby says new role is first since The Crown she wanted to "go really deep" into

BAFTA TV Award winner Kirby told Deadline: "And so, they sent me the script for it, and then I met Kornél [Mundruczó], the director, and I just was in love with it. It’s an exploration of grief, and how everyone experiences grief differently. I hadn’t seen a film about this sort of subject before, really. When I met Kornél, we had the best afternoon together, and I just knew that it was something I really wanted to do, so I felt incredibly lucky."

The 32-year-old actress plays the wife of Hollywood star Shia LaBeouf, who was already attached to the project, and the duo went to birthing classes incognito to prepare for the role, which involved a 30-minute continuous take of the actual birth.

The one-take scene was harrowing to film for a woman who hasn't had a child. "Well, right from the beginning, Kornél wanted to shoot it as a one-take, and Shia and I were so excited by it, because it’s like a dream, really, to do that as an actor."

She said they wanted to open Pieces of a Woman a bit like Saving Private Ryan, which sounds ominous, and she worked with an obstetrician and was allowed to be with a woman when she gave birth.

"Honestly, I look back and I couldn’t have acted that," she said. "I would have been pretending if I hadn’t really seen someone go through it for five or six hours, which she did. It was the most generous thing anyone’s ever done for me, allowing me to watch."

Kirby also has another film premiering in Venice: The World To Come is an American frontier story set in the mid 19th Century about a woman, Tally, who finds a deep love with her neighbour Abigail (Katherine Waterston) in a very male world.

She saw comparisons between Tally and Princess Margaret: "Those women that can do so much with their lives that have so many restrictions on them. They’re strangled by the things that they’re born into, the places that they’re born into, but also the psychological limitations that they put on themselves. And Margaret in The Crown is exactly that."

She "loved" playing the princess because it really is someone who is the biggest personality, that’s caged in this institution, that so wants to express who she really is, but is so inextricably linked with the four walls of that institution.

"I love exploring those people," she said.

Kirby is also reprising her role as White Widow in Mission: Impossible 7.

"...We’re starting in September, so that’ll be nice, because I really liked that character," she said. "I just like how weird she is and unusual and she’s really fun to play, so I’m really looking forward to that. And what’s next? I don’t know yet. I’m just waiting for the right thing. With these two films, I just so loved them, and I think my aim really is just to play as many different characters as possible. Ideally, as different as I can."

Looking for something else to watch? Check out our guide to the best TV series on Netflix and best movies on Netflix, or visit our TV Guide.