It’s obvious, even from the first couple of scenes, that “Next To Normal” is designed to be impressive. The musical, as the play’s program helpfully points out, won a Pulitzer in its original Broadway run. It features impressive songwriting, trios and quartets that erupt out of petty arguments; a whirring plot that builds family drama and mental illness all the way into drug abuse and shock therapy; and ballads designed to tear your heart out. In this performance, however, the actors reach for the same drama, the same pathos and the same notes — finding them just beyond their belting range. You can imagine the target, but the feeling doesn’t quite land.

“Next to Normal”’s plot, fittingly, focuses on the idea of living in the shadow of something else. Diana Goodman (Rachel Goldstein ’16) is haunted, literally, by the early death of her son, Gabe (Jordan Schroeder ’16). Gabe died as a child, but Diana imagines that he has grown up, and pays more attention to him than to her daughter, Natalie (Tory Burnside Clapp ’15). This arrangement means that Gabe follows Diana around for most of the musical, glowering. Schroeder carries this off with a series of color-coded shirts (once shirtless), and a broad maniacal grin, though his voice, struggling in the higher register, didn’t have the strength to make his presence as nerve-wracking as it could have been. Meanwhile, Natalie practices piano etudes and falls for a stoner boyfriend (James Lee ’16), who puts in a valiant effort to be edgy, despite never unbuttoning the top of his shirt.

As the musical progresses, Diana’s illness gets increasingly out of hand. Her husband (Carter Michael ’15) pushes her through a series of psychotropic therapies with the help of Dr. Fine at first, and then Dr. Madden (both Skyler Ross ’16) — yes, the names are meant to be meaningful. As a shrink, Ross exudes just the right, unsettling level of white-coat-powered exuberance, as he lists drug names like flavors of candy. But the doctor’s performance overwhelms Goldstein’s Diana, who uses her wavering soprano voice well during moments of moving fragility, but remains too restrained when she is supposed to become unhinged. When she tries to struggle out of a shock therapy room, for instance, Goldstein seemed more a rag doll than a woman on the edge.

Part of the performance’s softness was due to constrictions of performing in the Saybrook Underbrook. “Next to Normal” includes a generous portion of rock influences in its soundtrack (presumably for a modern flair), but the electric guitar-infused orchestra tended to overwhelm the efforts of the non-mic’ed performers. The musical’s set-piece songs were made for a booming Broadway stage, and here they feeling hemmed in and claustrophobic. At one point, one of Goldstein’s quiet solos was nearly run over by the wandering melody of a particularly out-of-tune, amplified violin.

Still, there were moments when performers successfully took matters into their own hands. Clapp, who co-directed with Ben Symons ’15, stole most of her scenes with a totally believable, hands-in-her-pockets portrayal of an angst-ridden teenage girl. In Natalie’s big song, “Superboy and the Invisible Girl,” the daughter complains about how her parents spend more time on her dead brother than her. But, watching Clapp perform, whether she’s dishing out a nearly fourth-wall-breaking quip, or choking back tears with wavering lips, you can’t believe that she’d ever lose your focus, much less disappear.

But even when “Next to Normal” rises to the occasion, you can still feel a better performance lying behind it. Clapp and Symons’ staging includes a set of mirrors at the back of the stage. By the end of the performance, the performers reverse all four to reveal each one’s shattered backside. This device seems to track the relative sanity of the main characters, like a sports game’s noise-o-meter. Through them, you are reminded that the Goodman family is in a pretty bad state. And sure, the plot tells you that. Over two hours, the actors work through motions of sanity and insanity. But, without the extra push, without true, ferocious highs and lows, it’s not quite enough. This is almost normal; madness lives elsewhere.