Rebel Hearts follows the Sisters of the Immaculate Heart of Mary in Los Angeles; a group of revolutionary nuns who defied the Catholic Church to defend their rights. They were deeply devoted to a life of service and formed a community that empowered not just sisters, but every woman in their sphere. True progressives and social activists, they fought to make changes in the church to make it consistent with the modern world and faced massive resistance from the patriarchy of the Catholic Church. Their story is one of true humanitarianism — a lifetime of activism that spanned from the Selma to Montgomery March in 1965 to the Women’s March of 2018. All along the way, they redefined what nuns and women could be.

The story of the Sisters of the Immaculate Heart of Mary starts in the 1960s when women had very limited options. For the most part, they could get married to men and be housewives or... they could get married to men and be housewives. The convent provided one of the few acceptable alternatives to that life. For many young women, it was almost a choice of joining a sorority or joining a convent. At that time, the practices and rituals of the convent were archaic and cultlike; they involved wearing a wedding dress during the initiation into the sisterhood to signify a marriage to Jesus as "brides of Christ," and having a schedule so severe it even dictated a bedtime. Change was desperately needed. 

Rebel Hearts producer Shawnee Isaac-Smith began working on the project more than 20 years ago. When Isaac-Smith was in college, she met one of the sisters and was amazed and inspired by her story.

Isaac-Smith was raised Catholic but stepped away from the faith "partly because of the way women were treated in the church." Later on when she went to film school, she carried the story of the sisters "in my little basket of stories I wanted to tell."

A sister introduced her to the Immaculate Heart of Mary community.

"They had been approached by many different people but didn't feel that they could trust them to do the story. And with this introduction, I was able to gain access to this very intimate group who had their own trauma throughout the years, and protected their story and wanted it to be told. I made them a promise that if they allowed me to tell the story, that I would finish it. So, who knew that it would take 20 years to finish it? But with the help of [director Pedro Kos] and the rest of our team, we were able to bring that to fruition." 

Kos signed on to the film in 2015. He "fell in love at first sight" with the sisters and their stories; when he saw their interviews with Isaac-Smith, he was "blown away by their imagination, by their perseverance, their tenacity; by their extraordinary intelligence and their foresight." As someone who had been raised in the Catholic Church, it really spoke to him.

"As someone who grew up Catholic, I'm still Catholic, but with major issues with the institution of the church, I felt like this story really needed to be told, really sparked my imagination in a way that few stories had in the past. And so I knew I wanted to help tell it," he said. 

The approach to writing a documentary comes not before filming, but after.

"We always say in documentaries that a lot of the writing actually takes place in the edit, after everything is filmed … you really have to immerse yourself in the materials," Kos said.

"We had these really long stringouts of interviews and stories, and it's really a process of creating that structure. I'm a very big proponent of index cards, so I can visually visualize the structure. We had a wonderful dialogue with our fellow co-writer, Erin Barnett, on how to really captivate and frame the story ... so that we would really put the viewers in the shoes of these women and take them on that immersive ride." 

Isaac-Smith says that from the very beginning, she saw the hero's journey. 

"A very obvious hero's journey, even a David and Goliath kind of subplot in there. And I think that kind of framed the overarching theme of the whole film. We had so much material and so many amazing stories. It was very hard to choose which of these characters we were going to highlight to tell the story because they were all on the same journey, but they all had their individual journeys as well. And they were such interesting, articulate women and so educated, that finding those little jewels and putting them together was a treasure trove," she said.

"We had to lose a lot of wonderful things on the cutting room floor because there were just so many gems in there."

The works of former Immaculate Heart of Mary sister, artist Corita Kent, played a huge part in the story as well.

"[Kent’s] art really kind of magnifies and punctuates a lot of the story," Isaac-Smith said.

"It was really fun to see how her art reflected back what was happening in the community at the time. And Pedro so masterfully used that as a character in the story to really bring it to life."

According to Kos, Kent's work guided some of the crew's decision-making processes. 

"We had this saying in our edit room, which was, ‘What would Corita do?’ Which for us was a code for think outside the box. Think differently. Like the Immaculate Heart sisters. Dig deeper," he said.

"It was a real treat to have [Kent's art] as sort of a guiding light. The writing process was not only the spoken words; it's Corita's art. It's the letters, it's the photos. Because there is so much of the story that felt tactile, you feel like it puts you there in the moment. For example, that correspondence between the community and the archdiocese or the headlines that are being made ... a lot of the writing process also was to immerse ourselves in the correspondence and the audio recordings, in the photographs to help envision how to bring that to life." 

The animation and graphics were key to making the story cohesive.

"We began to really track the arc of what the animation and the graphics were really going to do, the evolution from oppression to an awakening, to an opening," Kos said, noting the animation evolves as the story progresses.

"If you look at the style — the faces of the sisters, of the nuns and the animation — they actually begin to take on more detail. You see they become more personalized and become more individualized and become more true to themselves. And that's really this journey of this community that comes into its own."

Isaac-Smith and Kos offer these words of advice to any aspiring documentary filmmakers:

"Hold on to your vision. If there's a good story out there, hold on to that because the world needs to hear these stories to be inspired. And that's what filmmaking is all about," Isaac-Smith said.

"In the spirit of the Immaculate Heart sisters, collaboration … it took a village for the Immaculate sisters. It took a community to create the change and it also takes a community to create these films … [the Immaculate Heart sisters] knew that each and every one of the sisters brought a unique gift. And I think we all bring a unique gift to the work that we do," Kos said.

Rebel Hearts is now available to stream on discovery+ and is showing in select theaters.