The promos for Ryan Murphy's HBO drama keeping getting more and more powerful.

The first full trailer shows Mark Ruffalo, his onscreen partner Matt Bomer and Julia Roberts fight to raise awareness about the AIDS epidemic in New York City in the early 1980s. The pic follows gay activists and the medical community as they try to expose the truth about the crisis. At one point, Ruffalo's character accuses the government of a conspiracy to murder all gay men.

"To win a war, you have to start one," Ruffalo says in the clip.

Larry Kramer himself scripted the TV adaptation of his hit 1985 Tony-winning off-Broadway play. The HBO movie, which also star Taylor Kitsch, Jim Parsons and Alfred Molina, will air on May 25. Jonathan Groff, the star of another HBO program, "Looking," also makes an appearance in the telefilm.

HBO is already eyeing a sequel that would follow Ruffalo's Ned Weeks through the 1990s as he tries to help those dying from the disease.

2014 Variety Media, LLC, a subsidiary of Penske Business Media; Distributed by Tribune Content Agency, LLC