Sean Penn is the director, and he also stars alongside his own daughter, Dylan. This is being called her breakout role.
Dylan says she never wanted to be an actress, even with two parents in Hollywood: Sean Penn and her mother, Robin Wright.
The film is based on a true story of a young woman's tumultuous relationship with her con-man father.
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I talked to them about working together on this emotionally and physically gut-wrenching piece.
"Because she had to go into such painful areas at times, there were certainly those moments where I felt I needed to call Child Protective Services against myself just by asking her to go into those places emotionally," Sean says. "She is an actress, and what an actress she is. She went all the way in, and it's really extraordinary to watch."
Dylan plays Jennifer Vogel, and the film is based on her memoir. It's a role she says she couldn't pass up.
"The is my first, and the biggest role I've ever taken on," Dylan says. "It also felt like a big responsibility to tell the true story of someone that's still alive and was a major part of this project. I definitely felt a lot of pressure to tell her story and do well by her."
The film also stars Dylan's brother and Sean's son, Hopper Jack Penn.
"Flag Day" hits theaters like the Ritz Five here in Philadelphia on August 27.