Bleecker Street has released a trailer for “Mass,” which will be in limited release in theaters in Los Angeles and New York City on Oct. 8, with a national rollout to follow.

Starring Reed Birney, Ann Dowd, Jason Isaacs and Martha Plimpton, the film follows two sets of parents who agree to talk privately in an attempt to move forward after one couple’s son killed the other’s son in a school shooting.

Written and directed by Fran Kranz in his feature-film debut, “Mass” examines both sets of parents’ anguish and grief.

Shot almost entirely in one room, the movie is “like a slow-burn group confession that’s also a debate, and it invites us to take a journey into the souls of all four of these people,” according to Variety chief critic Owen Gleiberman, who, in his review, wrote, “sitting with them in that room, we travel somewhere.”

While...