Roberts plays Dr. Emma Brookner in Ryan Murphy's acclaimed HBO film about the onset of the HIV-AIDS crisis in New York City in the early 1980s.
"[She was] very stubborn and tenacious [and] just [railed] against any kind of injustice," Roberts, 46, who is nominated for outstanding supporting actress in a miniseries or movie for the role, says in a special feature in The Normal Heart Blu-ray/DVD, available Aug. 26.
Matt Bomer, who is also nominated for outstanding supporting actor, praised Brookner's foresight. "[She was] so far ahead of her time, and [was] willing to treat these people who were dying of something very mysterious," he says.
The clip above also shows a pivotal scene from the film where Roberts's character demands the medical community take action against this crippling disease.
Larry Kramer, who penned The Normal Heart for the stage (originally Off Broadway, then Broadway) before adapting it for HBO, fondly remembers the doctor.
"She was crippled from childhood polio," he says. "She was the only doctor in New York who would see us. She fought and she fought. She was wonderful and I loved her."