His Three Daughters cast had to be 'open and vulnerable' to explore grief in film

Watch: His Three Daughters stars Elizabeth Olsen and Carrie Coon discuss Netflix film

His Three Daughters tells a heartfelt story about grief and loss through the experiences of three sisters reunion to take care of their dying father, which required the cast to be "open and vulnerable" on set, Carrie Coon and Elizabeth Olsen tell Yahoo UK.

The Netflix film is full of deep conversations about family, life and death with each of the characters being forced to reckon with not only their father's ailing health but also their own faults, and the way their relationship has deteriorated over the years. Olsen and Coon are joined by Natasha Lyonne in the movie as Christina, Katie and Rachel, respectively, with the trio taking on the bulk of the script and tapping into their vulnerabilities to make their characters feel real.

"I think we understood that by virtue of the fact that we all signed up for it and it was so clearly that on the page what it was, we knew who we were getting, we knew everybody was going to show up," Coon tells Yahoo UK about the emotional challenge presented to them.

"We had three weeks to film it. We had to be open and vulnerable, and prepared, and I think we all knew that we respect for each other, we knew that's what was going to happen."

Olsen concurred sharing how director Azazel Jacobs gave the cast space in which to explore their characters emotions through several days of rehearsals so they had it clear in their minds what they had to bring to set.

"We had that time to work through facts that are simple that we need to understand about timelines of our past living together, not living together, whose parent died when," Olsen says. "Then also we had to find a rhythm with one another, which was a big part of those rehearsals, and a way we got to start learning about one another as people as well, and have that time."

Jacobs was impressed with the way Olsen, Coon and Lyonne dedicated themselves so fully to the task at hand, telling Yahoo UK: "There wasn't a day shooting that I didn't come back like, 'wow, what a gift'.

"They just kept delivering, I think that they are brilliant. I knew that they were brilliant but then when you see them coming and giving you everything that they have each day, coming so prepared before shooting, just treating the project with such respect.

"Pretty much every day I'm asking them to like to take out their heart, put it in their palm and raise it to this [camera] angle and that angle, [and] hold it up to the light. That's what it felt like, and they were like 'yeah, we're up for doing that'."

The film's theme of death and the acceptance of it, and the grief that comes with losing ones parent —with prior warning or otherwise— is essential to Katie, Rachel and Christina's healing journey. And director Jacobs drew on his own experience with the idea of death to inform their story.

"My parents had hit a certain age and there was health issues that brought my wife and I back to New York City to be with them, and I suddenly was trying to learn how to become a caretaker," the director says. "And the whole thing was shocking, surprising, and confusing, and I think, for me, trying to write and make this film was a way for me to bring in this thing that I love, which is filmmaking, into something that was very hard to get my head around.

"I also just tried to confront some of the fears and hopes that I had with this situation sadly approaching, that had once seemed so far and now was suddenly there."

The director's approach to its subject matter, and the idea that other types of families to the nuclear family exist —as Lyonne's Rachel was adopted when their father married her mother— was something that the cast revelled in.

Coon adds that the film "felt very real to [her]" because of how Jacobs approached the relationships within the story: "To me, the dynamics in the film, the relationships, felt so specific that it just felt like real people to me, even though the movie is kind of theatrical because of how much language there is.

"There was never anything that felt like a big movie scene about somebody dying, it all felt like real people in real time dealing with their grief as it occurred to them. And that seemed to me to be a very instructive, moving and honest experience."

Olsen says she was "really excited about the language" because it was something she hasn't been able to do much of in her career which, for many years, has seen her play Scarlet Witch in the Marvel Cinematic Universe.

"What I loved about how he is depicting a family is how we create these ideas and roles for the people in our lives and our family, and then we even ourselves perform to those roles that are assumed of us," Olsen reflects. "And I definitely can relate to that, and I think when you disrupt that order it really can throw off a family as it does in this film."

Coon concurred with her co-star, adding: "I just think we all have somebody in our lives who operates that way, maybe in our families, and grief is the crucible that brings all of these things to the surface.

"And anyone who's been through it, maybe with or without siblings, your whole history is present in those moments as you're contemplating what the ramifications are of this absence. It's all there to be provoked or suppressed."

His Three Daughters premieres on Friday, 20 September on Netflix.