• David Dilego, left, and Adam Cunningham

In Parasite Drag, a powerful night of theater awaits audiences. The one-word review is “intense.” George Pierce’s direction gives the actors the confidence to reveal the raw fury of their characters, and Mark Roberts’ script tries to up the ante on the long theater tradition of stories about dysfunctional families.

Set in rural Illinois, the play brings together two brothers who have endured a long, bitter estrangement. Gene is rigid and respectable, steers his life by the Bible and has settled into a loveless marriage. Ronnie is content as a janitor, happily married to an even freer spirit, and he’s willing to break the long silence by visiting his brother as their sister lies dying in the final stages of AIDs.

This is enough of a situation to trigger an exploration of the two brothers and their wives, but Roberts is more concerned with accumulating woes than exploring their effects. The plot doesn’t have time to dwell on any of them, but we rocket through several sexual taboos, drug addiction, self-mutilation, infidelity, suicide, mercy killing and religious conviction. These elements serve as justifications for the play’s volcanic passions, but because they generally occur in the past and often to offstage characters, they feel more like grim headlines than experiences that engage our compassion. Dark humor leavens the mix.

In an ideal theater production, we feel compassion for the characters, catharsis from participating in their emotional lives and connoisseurship for admiring — from a distance — bravura performances. But sometimes a show aims at only one of the three.

Roberts and Pierce drive our attention to the performances. Roberts has loaded plenty of powder (in the form of traumatic backstory) into Parasite Drag to shoot all four human cannonballs high in the sky. Pierce gives his actors the courage and conditions to express their needs with scorching intensity. The result is four impressive, no-holds-barred performances. The audience leaves drained, yet marveling that these actors have the strength and psychological daring to propel themselves through the artistic ordeal.

On this count, the production is a success. See it to admire actors working bravely together to portray the effects of harrowing external events. This is an accomplishment, and the “but” that’s coming isn’t intended to diminish it but to observe that theater has other objectives, too. You can spend this show as a dazzled spectator, but it’s harder to invest yourself in the characters.

For that, you need a stake in their struggles. Roberts has a tendency to let the objective significance of an event stand in for its subjective experience. Imagine getting no closer to the three women held hostage in that house in Cleveland than seeing the TV news footage. The feeling is horror, not empathy.

But when he’s not tossing problems at his characters, Roberts shows outstanding dramatic intelligence. The play begins with a thoroughly realized scene of domestic misery at a low boil. The lights come up as Gene and his wife Joellen, are stirring the dregs of a fight. The scene begins as the conflict has ended, but husband and wife are secretly looking for a way to prolong it and claim victory, while ostensibly patching things up.

The playwright’s skill in getting to the heart of how these two battle, and the actors’ quiet work in showing how the characters make do with the distance between them, are stunning. In this scene, we don’t yet know or need to know the particular unfortunate events of their lives. We participate in a human experience that doesn’t take AIDs, rape or a terrible childhood to detonate. It just takes two people and the baseline friction of a marriage.

Adam Cunningham plays Gene with all the inflexibility the character demands, and without letting the premise collapse into parody. Cunningham is able to make Gene sympathetic, and he doles out the little mysteries of his heart with admirable restraint. But sometimes he works the role like a mountain climber, hitting a plateau and staying right there, then ascending to the next peak. This tendency to stake out a territorial claim on an emotion leaves Cunningham waving the same flag for too long.

As Joellen, Ginger Pierce (real-life wife of director George) finds so many nuances that she completes a character the playwright has left somewhat undeveloped. Pierce is a true in-the-moment actor, letting her reactions flow from what’s occurring on stage. She’s good at choosing her beats, including the comedy to be mined from them, and she’ll risk taking time to let a moment fully unfold. Because Pierce lets Joellen’s tragic détente with Gene crush her, it feels sadder than the more sensational troubles in the story.

Sarah Mell is a fierce, fresh face onstage, investing herself fully in her role. She uses her height and dancer’s poise to walk with a strut as Ronnie’s wife, Susie, the one character who has an instinct for love and trust. Mell does a lovely job of hanging back as the peaceful visitor and then springing out to assume the catalyst’s job of stirring things up. Her work is based on surprising us, and she’s wildly good at it.

As Ronnie, David Dilego combines a rough-and-tumble appearance with a flagrant chip on his shoulder. The effect puts too much emphasis on the character as untrustworthy lout, while the playwright has written a softer, contemplative side to round him out. Dilego gets close to this duality occasionally, but whenever the script calls for anger, he lets fury rule his performance. The ember of pain that sparks these fires is far less visible than the conflagration. But Dilego’s conviction onstage is thrilling to watch.

Roberts has chosen a play title that begs for explication, and reviewers must oblige. “Parasite Drag” is an aerodynamics term referring to the drag forces from an airplane’s nonlifting surfaces, such as the fuselage. Roberts fastens onto the flying image as a metaphor for growing up, but he can’t quite stuff this obscure term into any character’s mouth. Instead, he twice tries to call attention to it by having a character wonder what the name is for such a thing. That’s not how metaphors work.

Roberts creates some remarkable moments in this play, but one can’t help feeling that he’s so busy completing a collection of miseries that he can’t take time to let his characters reflect on them. He never lets up, and a play that starts with a tornado siren has to end with the ultimate deus ex machina, a genuine act of God. In between the warning and the twister, Parasite Drag is a furious ride.

"Parasite Drag" by Mark Roberts, directed by George Pierce, produced by Waterbury Festival Playhouse. Wednesday through Sunday, September 4 to 7, and Wednesday through Saturday, September 11 to 14, 7:30 p.m. at the Waterbury Festival Playhouse in Waterbury Center. $25-27. Info, 498-3755. Children under high school age not admitted.

The original print version of this article was headlined "Dysfunctional Dynamo."