In new film 'Mass,' parents of victim, perpetrator in mass shooting try to heal

It's tough. It's stressful. It's gripping. But you might not be able to look away as the drama unfolds in the new movie, "Mass."

"Mass" tells the story of two sets of parents who agree to meet in a room in a church to talk out a tragedy that happened six years earlier. It's something they need to do face-to-face in order to try and finally move forward from the terrible grief and anger they still feel.

"These are people in pain," said actor Jason Isaacs. "They come into a room. My wife, I think, is the one that's messed up. I think I'm fine. The audience knows perfectly well that I'm not fine. And they're reaching for something better."

"They're trying to find some acceptance or healing or possibly forgiveness in their lives. They don't get to leave, you know? They have to do the work. And I wanted to honor that by having this conversation be in real time. They enter the room and we don't get to leave until they leave," said director and writer Fran Kranz.

In one moment of the film, a mother says, "Tell me about your son." A father asks why. The mother then says, "Why do I want to know about your son? Because he killed mine."

"Mass" is about a mass shooting. Recalling that scene, actor Reed Birney said, "Months later, I saw the movie and she said that line and I gasped. It's, I think, astonishing writing."

Isaacs called his experience in the film "the biggest emotional landscape I've ever been privileged enough to inhabit."

Actor Ann Dowd still feels the pain.

"I felt like a child with her," she said. "That she was just plain broken and had found a way to put herself on her feet but part of her has gone away."

"Mass" is rated PG-13. It's new to theatres this weekend.