Given the recent progress in HIV/AIDS research and gay rights, it’s a bit disquieting to return to the Tony-winning Larry Kramer play “The Normal Heart” in this movie treatment premiering on HBO Sunday.

The film chronicles the early days of the HIV/AIDS crisis, when the pleas of the gay community landed on resoundingly deaf ears.

It’s a different kind of horror story for director and “American Horror Story” co-creator Ryan Murphy, a picture about activists struggling to be heard (it’s centered on the founding of Gay Men’s Health Crisis) while their community is ripped apart by an inexplicable plague.

Kramer co-founded GMHC and was heavily involved in this early period. The protagonist here is the fictional Ned Weeks (Mark Ruffalo), based on Kramer himself, and the movie finds its dramatic center in his profound outrage at both the ignorance and disinterest of the wider world and the nonconfrontational tactics of his fellow activists.

The film feels a tad stagebound but the acting is terrific and the reminder of how far we’ve come — and how much further there is to go — is essential.

‘The Normal Heart’
3 stars
Airs on HBO on Sunday at 9 p.m.