Jennifer Hudson

Jennifer Hudson traveled to a dark place for her latest film role. The Oscar-winning actress stayed in a prison cell for three days so she could channel apartheid-era icon Winnie Mandela for a biopic.

In order to depict the 500-plus days the former wife of Nelson Mandela spent in solitary confinement, the svelte Hudson confined herself day and night to a prison set in South Africa. She tells Newsweek that she wanted to “experience some of the hell that woman went through.”

By the third day, she started to lose her mind. Her physical appearance had deteriorated and she was having imaginary conversations with her son. The harrowing experience left her emotionally and physically exhausted. “They snatched her out of her home and she had no idea what happened to her children,” Hudson says of Mandela. “Imagine living that? This was her life! This was real. As a woman, I am angry for her, hurting for her. And as a mom? God, being in solitary confinement, away from my son just for five days when shooting those scenes—it was too much for me. I was drained and stripped down. I was changed.”

The film has stirred controversy after the real Winnie Mandela threatened legal action to halt production. It is expected to hit theaters by September, while Hudson’s sophomore album I Remember Me is due March 22.