Last night (May 25) HBO viewers witnessed Hulk actor Mark Ruffalo take on his most challenging role to date, as a gay rights activist living in the early years of the aids epidemic of the 1980s. In The Normal Heart, Ruffalo stars alongside Matt Bomer and Julia Roberts as Ned Weeks, a man desperate to draw attention to the aids crisis which is plaguing the gay community.

Mark RuffaloMark Ruffalo stars as Ned Weeks in The Normal Heart

The character is based on real life activist Larry Kramer, who also wrote the film’s script based on his 1985 play of the same name. In order to prepare himself to take on the challenging role, Ruffalo spent time with Kramer, hearing his story and reading his works as well as remembering his own feelings witnessing the AIDS crisis in the early 80s. “It felt like a pandemic. And I was young, so I was still idealistic, and it was jarring to see the inhumane response to it all,” he told the Sioux City Journal. “It didn’t compute. But Larry was right, I didn’t fully understand how deep it went.”

More: See our pictures from The Normal Heart's New York premiere

Indeed at their initial meeting, Ruffalo said Kramer ‘tested’ him, by asking if he’d read the author’s 1978 work Faggots. Ruffalo did read it, later, and said it helped him “understand where the gay culture was before, where it was after, how prophetic Larry was. He was already saying, ‘We are not the sex that we’re having!’’

Now, nearly 30 years after The Normal Heart was first staged, it is still as relevant and important as ever, even if the original activists achieved their goal of raising the awareness of the disease.

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In 2012 Kramer set about writing the movie, adding new scenes to the point where the film has become vastly different from the original play. “The play was meant to get you out of your seat, to take you out of your ennui and drive you to action," said Ruffalo. “But a lot of time has passed, so it becomes something else. We don’t have to shake the audience out of apathy. What we do is deepen the picture, show what kind of journey we were on that led us to where we now find ourselves,” he explained.

Mark Ruffalo and matt BomberMark Ruffalo and Matt Bomer at The Normal Heart's New York premiere

Now The Normal Heart is “less about AIDS than it is about love,” said Ruffalo. “That’s what blasts through! That’s what carries them! That’s what saved them! It’s the grace. It’s so powerful. It’s so moving. Love in every sense of the word, every permutation.” A message that truly is still as important and powerful as ever.

The Normal Heart premiered on HBO May 25th