Physics concentrators, forgive me if I mangle this explanation: “rabbit holes,” as postulated by physicists, are short-cuts through the fabric of space-time that take us to other versions of this universe. At the denouement of David Lindsay-Abaire’s play “Rabbit Hole,” the bereaved mother at the center of the play finds unexpected comfort in the concept of alternative realities, that perhaps “this is just the sad version of us.”

Audience members may also find comfort in the idea that this production is just a mediocre version of the show, and that in some happier universe, lazy direction and one-note acting are not distorting what is actually a very good play.

The Huntington Theatre Company has brought “Rabbit Hole” to Boston directly on the heels of a Broadway run that earned five Tony nominations, including one win for Cynthia Nixon, who originated the role of the mother, Becca. What is confusing about this production, running through Dec. 3 at the Boston University Theatre, is that the raw material in Lindsay-Abaire’s script is so excellent—in the deft hands of Nixon and Tony-nominated director Daniel Sullivan, it must have been an emotional Tilt-a-Whirl.

This production runs more like an emotional steam-roller thanks to John Tillinger’s blunt direction, barreling forward with a schedule to keep. The script’s writing is nuanced enough to transcend its “Lifetime”-esqe sappy subject matter, but here it gets a treatment that silences all but its most blaring notes.

The play begins eight months after Becca (Donna Bullock) and her husband, Howie (Jordan Lage) lose their four-year-old son, who is hit by a car after chasing his dog into the street. In one illustrative struggle, the couple gets into a scalding dispute over the dog, who has been sent to live with Becca’s mother, Nat (Maureen Anderman).

The dog is getting fat, Howie says, but Becca refuses to have it in the house. Howie clings to the dog as though it will bring the boy back, and Lindsay-Abaire conveys to the audience that this dog represents the emptiness of Howie and Becca’s dead son. These are people you have probably seen before, but rather than rely on our familiarity, Lindsay-Abaire uses it to his advantage to eliminate cumbersome backstory and instead focus on the extraordinary depths of his characters.

The only actor who fulfills the promise of the writing is Lage as Howie, who gives us a husband who is fundamentally understanding, but too tired to keep laboring at his fractured marriage. Even when Becca’s sister Izzy (Geneva Carr) questions Howie about what appears to be an affair, we manage to identify with the frustration that led him there, even as we are disgusted by his ineffective attempt to deny it.

Carr as Izzy and Anderman as Nat come off with similar degrees of blandness, which is disappointing, given the wildly different nature of each character.

Izzy is the “fuck-up” sister, whose unplanned pregnancy is one of the cerebral screws Lindsay-Abaire adds to the play. He practically hands Carr one of the show’s most brilliantly twisted scenes (which he is ballsy enough to place just after the curtain opens), in which Izzy tells Becca the she is pregnant even as the latter folds her son’s old clothes for Goodwill. But Carr manages to fumble, not at all emphasizing the cruelty in the exchange, and the audience hardly realizes the scene’s maudlin undercurrent before it ends.

While Anderman’s performance is more skilled than Carr’s, Nat fades into extraneousness by the end of the play. She is the kind of air-headed mother who their children hate to love, but Anderman lacks the reasonable core than would have given her some weight in the story.

Troy Deutsch as Jason, the teen-age driver of the car that killed the boy would have suffered similarly if the script had not shoved him into the play’s climactic moment. Jason is an amalgamation of every nerdy-sensitive teen ever to hit the WB, but beyond that we get very little from his character.

Weakest of all is Donna Bullock as Becca, despite the fact that the part is so beautifully written. Her performance we miss the fragility that rounds out the character and allows us to sympathize. Rather than being grief-stricken, this Becca comes off as merely irritable, and one can hardly blame Howie for wanting to stay out of the house.

James Noone’s set, a slide-show of rooms sliding (creakily) in and out of the frame of the house, is a bright spot of the evening, transitioning inventively from perfect suburban kitchen to perfect suburban living room to the child’s heart-breakingly adorable bedroom. A great set is lovely, but it cannot make up for an otherwise lame evening.

If you have a ticket already, seeing the Huntington’s “Rabbit Hole” won’t hurt, but if not, your time would be better spent looking for the real thing.