There’s an intentional obscurity at the start of Mass, the debut feature from writer/director Fran Kranz, that instantly placed it amongst the most intriguing premieres at this year’s Sundance Film Festival. We open on a church in a suburban town, meeting the volunteers as they set up a room in the basement for an impending meeting. Much attention is paid to the placement of the table, the positioning of the chairs, the proximity of a tissue box. We meet a social worker, clearly acting in the capacity of a liaison, who asks that the tissue box not be placed in the middle of the table — that would be weird. As long as it’s within reach. This much we can glean about Mass, after a simple Times New Roman title fades in on a black screen over dead silence: we’ll probably need tissues. But we’re not sure why, exactly, and yet we’re gripped all the same. The social worker moves the chairs from their even placement around the table, putting two on one side and two on the other.

Mass is no less interesting once the purpose of this meeting is revealed, but it’s a particularly refreshing opening in an age where most films assume an audience will lose interest if they’re not given all the facts up front. Every glance and seemingly-negligible line of dialogue becomes a potential clue, and it never approaches a feeling of purposeful obscurity or frustration. Before we reach that point we finally put the pieces in place: two sets of parents are meeting six years after a tragic school shooting in which one son killed the other.

Narratively, it’s somewhat remarkable to see a first-time writer/director with the confidence to resist telling this premise up front. Fran Kranz has a fairly sizable acting career behind him, but Mass shows a promising career ahead as a filmmaker on the other side of the camera. It’s equally surprising that this story hasn’t been told before. As one of the major issues in today’s America, gun control nevertheless gets only sporadic attention in narrative film. Those that dare tackle the issue typically find purchase in the event itself, exploring the victims and/or perpetrator as a way to either honor the former or make sense of the latter. But events such as this destroy the lives of others as well, and mining such tragedy at a six-year remove proves every bit as caustic as the moment it happened.

There’s a fair bit of Kenneth Lonergan in the DNA of Mass, and Manchester by the Sea is both an accurate and worthy comparison. As in that film, gut-wrenching emotion occasionally gives way to banal, trivial beats of comedy. A solid 90% of Mass takes place in that room in the church basement, monitoring the ebb and flow of the conversation between these two sets of spouses. Tears fall. The tissue box is retrieved from its discreet placement on the bookshelf and plopped in the center of the table. These four individuals attempt to make sense of the senseless, but once that door opens again to the outside world, the door also reopens to the mundane niceties of everyday social interaction. This might be jarring in the hands of a lesser filmmaker, but here — as in Manchester — the effect is profound: we understand the ways in which people mask unfathomable pain, and that they do it not for our sake but for their own.

It helps that the four central performances in Mass are some of the best you’ll see this year. Jason Isaacs and Martha Plimpton are ticking time-bombs from the jump, pained at the loss of their son, seeking to punish the parents of the killer who destroyed their lives. But they’re seeking some kind of redemption, too, and seeking to forgive as much as punish. They want to live again, quite simply, but they don’t want that to mean that they’ve forgotten their son. On the other side of the table are Ann Dowd and Reed Birney, conflicted in their own right, not daring to defend their murderer son but also unwilling to deny that they loved him. Isaacs, Plimpton and Dowd all put forth career-best work here, but it’s Birney’s Richard who proves the most interesting character. Richard is a proud man with a matter-of-fact personality, not prone to showing his emotions on his sleeve. The ways in which this jars with the other three people around him — including his wife — gives Mass a unique jolt.

Apart from an ongoing piano lesson up in the church and choir practice later on, there’s no music in Mass. The cinematography, too, is sort of silent for the first act of the film. We’re locked on a tripod in mostly wide or medium shots, recalling the ice-cold passivity of Paul Schrader’s First Reformed. Once tempers start to rise, Kranz goes handheld and gives us close-ups, pushing those pained performances into our lap. This unfolding works beautifully, and it leads to a catharsis that you wouldn’t think possible out of such a senseless inciting action. As a first-time effort, again, Mass is a gripping little film about a major point of contention in American society, and it announces Fran Kranz as a sharp independent filmmaker to watch.