After devouring it in one sitting, he knew the story would make an incredible film.

And he knew just the person to play Liptrot: four-time Oscar nomineeand his now wifeSaoirse Ronan.

I read it straight away and was so engrossed with Amys story and the poetry of her writing style.

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Photo: Courtesy of Sony Pictures Classics

Ronan carries the film squarely on her shoulders.

Lowden and Ronan signed on as coproducers and developed the project for two and a half years.

The team brought German filmmaker Nora Fingscheidt on board to direct the film and cowrite the screenplay with Liptrot.

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Photo: Courtesy of Sony Pictures Classics

At first I was really nervous because Ive never really worked that way before, Ronan says.

But it was the most liberating creative experience of my life.

Lowden never had any doubts in his former costar, however.

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Photo: Courtesy of Sony Pictures Classics

(He and Ronan met while filming 2018sMary Queen of Scots.)

Shes not an overly precious actor, he tellsVogue.

The main challenge for Ronan was performing the flashback scenes in which Rona is in varying states of sobriety.

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Photo: Courtesy of Sony Pictures Classics

But watching her reach a tipping point is what really grounds you in the reality of her illness.

Im kind of a purist when it comes to that, Ronan says.

(StudioCanal is overseeing its international distribution.

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Photo: Courtesy of Sony Pictures Classics

It does feel like theres been a shift, Ronan says of what she looks for in projects now.

Its all just reflective of where Im at personally or what Im craving creatively.

Having turned 30 earlier this year, Ronan is excited to embrace a new era.

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Ronan and Lowden at the Primetime Emmy Awards in September

As far as whats next, Ronan is open to the possibilities.

Shes like a Swiss Army knife.

Ronan likens her situation to a footballer whos served their time on the pitch and goes on to coach.

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Photo: Courtesy of Sony Pictures Classics

Shes certainly worked with enough directors to know how shed like to manage a set.

Its difficult when youre working with a director who isnt upfront about their intentions, she says.

I feel like I thrive when I know what the boundary is and I can work within them.

But she doesnt want to get too ahead of herself.

Both these filmsparticularlyThe Outrunare coming from very deep, interior parts of myself, she says.

I like to embody the person as opposed to just overintellectualizing everything, and thats such a freeing experience.