Patrick Torelle, as Robert, and Nicole Trobaugh, as Catherine, in 'Proof'

Patrick Torelle, as Robert, and Nicole Trobaugh, as Catherine, in ‘Proof’

David Auburn’s Proof, which runs through June 28 at Cottage Theatre, is a fast-moving, powerful drama that explores a daughter’s quest to escape the overbearing reputation of her late father, a brilliant university mathematician.

As the story opens, we meet Robert, the professor (Patrick Torelle), talking to Catherine, his daughter (Nicole Trobaugh), on  the back porch of the home they share in Chicago, where he is a professor at the University of Chicago. From the very beginning, though, we know something’s not quite right in this meeting. It’s one o’clock in the morning, and Robert has just remembered it’s his daughter’s birthday, and he’s presenting her with a bottle of champagne — which she proceeds to drink alone, right out of the bottle.

Trobaugh, as Catherine, with Kory Weimer, as Hal

Trobaugh with Kory Weimer

Soon enough we learn what’s wrong: Robert’s dead. The funeral is later today. And he’d been certifiably insane for several years before his death, forcing Catherine to put her own life and education on hold to take care of him in his decline, all while battling her fear that insanity will claim her, too.

Into this mess steps Hal (Kory Weimer), one of Robert’s graduate students, who is going through the late professor’s voluminous notebooks to determine whether any of his mature work comes close to the brilliant insights he published when he was young. Fending him off, and valiantly if irritatingly trying to save Catherine from herself, is her big sister, Claire (Janet Whitlow).

This is a taut, brilliant play. It won the Pulitzer Prize for Drama and the Tony Award for Best Play in 2001. The Cottage Theatre production, directed and designed by Alan Beck, perfectly tells the story of Catherine’s battle to emerge from her late father’s shadow: To prove herself, you might say, as a mathematician and as a woman.

Trobaugh, familiar to Cottage Theatre audiences from her roles in Steel Magnolias and The Glass Menagerie, is absolutely wonderful as the confused, lonely and resentful Catherine. Trobaugh has the remarkable ability to convey buckets of stage tears with authenticity, and can spin her emotions on a dime. Her combination of vulnerability and toughness keeps the character in constant but natural motion.

Torelle, well known in local theater, plays Robert with more sweetness, at times, than I expected to see; that’s a plus, as it would be easy to make the old professor always cranky and strange.

Weimer captures Hal, the drum-playing math student, with grace and charm; he and Trobaugh make the romance between their characters come across as both comfortable and believable.

Finally, Whitlow is suitably overbearing as the big sister, who makes more money but has fewer math skills — and much less emotional resonance — than Catherine.

Proof is a simple story with complex, layered themes. It touches on everything from love, trust and betrayal to the uneasy place of women in science and math, the relationship of genius and mental illness and, yes, prime numbers. Treat yourself to a satisfying night of theater and go see it.

Through June 28 at Cottage Theatre, 700 Village Drive, Cottage Grove. Tickets at