This Proof’s weakness comes from the thinness of its lead performances.

Proof by David Auburn. Directed by Michelle Aguillon. Staged by Nora Theatre Company at the Central Square Theater, Cambridge, MA, through February 18.

Lisa Nguyen and Michael Tow in “Proof.” Photo: A.R. Sinclair.

By Kamela Dolinova

Proof, the Pulitzer- and Tony-winning play by David Auburn, made a reassuring critical splash when it premiered at the turn of the millennium. Celebrated as an exemplar of the “well-made play,” the 2000 script proved that a taut but compassionate family drama, a ‘well-made’ play on on a single set, could still move contemporary audiences.

Somehow, despite the movie adaptation and frequent revivals, I haven’t see the play on stage until now. At this point, a production faces considerable challenges; the original production, with Mary Louise Parker in the lead, has become legendary. Any new production of Proof has to justify its existence — will it live up to expectations? The answer provided by this Nora Theatre production is yes and no. The staging is competent but low-energy, to the point that a number of dramatic opportunities are missed. But there is enough here to convey the great power of the script.

The play focuses on the plight of the 25-year-old Catherine (Lisa Nguyen), who depressed and directionless following the death of her genius mathematician father, Robert (Michael Tow). She dropped out of her own mathematical studies to care for him as his mind deteriorated, and worries about inheriting her father’s mental instability along with some of his talent. Her successful and uptight older sister, Claire (Cheryl Daro), cajoles Catherine into moving to New York. She promises Catherine an exciting new life, but is quietly planning her sister’s coming mental breakdown. Meanwhile, ex-grad student Hal (Avery Bargar) pores over the professor’s notebooks, searching for some final note of brilliance amid the cacophony of his graphomania. Catherine vacillates between attraction to Hal and distrust of his motives; she suspects he is searching for something he can steal and publish as his own. But, after a night together, she trusts him enough to show him a notebook of her own: it reveals that she has cracked an important mathematical proof.

Then the big reversal comes. Hal and Claire disclose their skepticism about Catherine’s work. Long before the term “mansplaining” was coined, the protagonist experiences it in its most insidious form: her work is denigrated, her word doubted. The one accomplishment that might have moved her beyond depression and grief into a world of meaning is stolen. The notebook is handed over to the men in Hal’s math department, who will determine its “authenticity.” Claire epitomizes narrow notions of success and femininity, to the point that she participates in the lie – and reveals her doubts about Catherine’s sanity.

Auburn’s play is ostensibly about math, but it is merely a background for the exploration of the calculus of familial trust, love, grief, and loyalty. These themes are universal, so Nora Theatre Company artistic director Lee Mikeska Gardner made the refreshing choice to have Asian-Americans direct and play the script’s father and daughters. Given Boston theater’s terrible record on inclusiveness, Gardner’s efforts in this regard are admirable.

The production sensitively and sensibly steers away from stereotypes. Its weakness comes from the thinness of its performances. Granted, the role of Catherine is a notoriously tough one to crack. The part requires subtle resonances of instability — generated by personal sacrifice at the altar of long parental illness as well as complicated grief at its ending. The character needs to be smart and sharp as well: there should be the sense that — underneath the heavy flannel blanket of depression — Catherine has a quick and inquisitive mind, an intellect that has been dominated by responsibility.

At this point in her career, Lisa Nguyen comes off as somehow too young, too soft, to create the impression that the role of Catherine calls for; her complaining is not prematurely world-weary but somewhat whiny. Her relationship with her father, the reflection of five hard years of caring for him in his decline, is not convincing. Their interactions feel awkward: not the chafing of a strained relationship between tight-knit family members, but the irritation of people who were never close enough to get under each other’s skin. More important, it is hard to believe that she authored the proof. Not because — as the play’s characters lead us to think — she is female, or she is “unstable,” or she doesn’t have the smarts. The problem is that Nguyen doesn’t make the most of the moments Auburn provides to suggest Catherine’s brilliance. The actor’s gestures and emotions often feel non-specific.

Michael Tow, who has the unenviable task of playing the dead man, similarly struggles. Both he and Nguyen had a number of line flubs, and while his fine resonant voice and fatherly aspect do well for an initial characterization, he doesn’t navigate the mercurial shifts that Robert requires. The great mathematician, whom Hal worships, doesn’t swell to his full size in the scenes where he is meant to be the Genius Professor. Similarly, when his sanity is in question – particularly in the late scene in the winter’s chill – he doesn’t escalate the tension enough. The script provides a clear and heartbreaking moment where Catherine realizes that her father’s seeming recovery is, instead, a relapse. But both players keep the interaction so small that the emotion doesn’t read. Supporting cast members Daro and Barger do an admirable job of keeping the text hopping, making their cutting or touching lines land. But Tow and Nguyen, who sit at the heart of the play, don’t quite keep the blood pumping.

Some of the blame can be laid at the feet of director Michelle Aguillon. At times she stages critical scenes in ways that undercut their dramatic effectiveness. Actors are turned so that their faces are impossible to make out from one side of the audience, or a character faces upstage, his or her face hidden from everyone.

The show’s production values are high; the world the actors inhabit feels autumnal and real. Little details of Janie Howland’s single back-porch set, such as weeds coming up around the steps and broken trellises, pay subtle homage to neglect. The math symbols scrawled on the blackboard-green face of the house itself lend a dreamlike touch without breaking the atmosphere of naturalism. Grant Furgiuele’s piano-driven music cues and sound design generate the proper tensions and releases. Still, scenes that should crackle with psychological life tend to lie flat, and the shifting motivations of the characters — Catherine’s in particular — feel unclear.

All this is a shame, because the cast is talented and the script’s strengths, despite the staging’s deficits, are evident. This particular Proof is more like Catherine’s description of her own work — “lumpy,” “stitched together” — than it is elegant.

Kamela Dolinova is a writer, actor, director, healer, and person with too many jobs. She loves the community and little theatre scenes in Boston, and has recently enjoyed working with Flat Earth Theatre, Theatre@First, and Maiden Phoenix Theatre Company. She also blogs at Power In Your Hands.