Patrick Thomas O'Brien, and Maggie Cramer Photo by Alyssa Christine Photography

Catherine is a twenty-five-year-old woman who has spent years of her life taking care of her father Robert, once a brilliant mathematician at the University of Chicago, whose early descent into a mental illness robbed him of his career and, finally, his life. Catherine had some of her father's genius for math but her options were cut short when she dropped out of college after just a year because Robert's remission ended and his descent into madness resumed. Robert died this week and his funeral is tomorrow. Catherine's older sister Claire is flying in from New York, where she has a successful career and a long-term boyfriend, for the funeral and to address some of her family's affairs.

During his year in remission, Robert was well enough to return to teaching and advising, even though not able to do any original work in his field. During that year, he steered a discouraged PhD student named Hal on track to succeed. Hal is now in Robert's study, poring over the stacks of notebooks which Robert filled with his fervent musings during his years of decline, on the chance that somewhere in his mentor's rantings he would find a bit of brilliance. Catherine is certain that Hal will find nothing. She urges him to give up and leave her alone with her grief, uncertainty about what lies ahead for her, and fears that perhaps she has inherited her father's mental disorder. This fear is exacerbated by the fact that, as the play opens, Catherine is on the porch having a conversation with her deceased father, who has brought her a bottle of champagne to celebrate her birthday.

As Catherine finds that Hal is not so easily dismissed and Claire has specific ideas about what Catherine's next move should be, an improbably brilliant mathematical proof emerges among the myriad of papers in Robert's study. Auburn creates a very feasible set of circumstances that entangle themselves before a resolution that feels well-earned and complete, even as it leaves the door open as to what direction Catherine's path might take from this moment on.

The dialogue is as true-to-life throughout, including between Catherine and her deceased father. We also see and hear Robert while alive in flashback scenes that effectively fill in blank spots in the narrative. The play tells a serious story, but not without rich humor. Catherine's sarcasm, though a symptom of her depression, is often sharply funny, and Hal's description of the debauchery at academic conferences is quite hilarious and rings true to those who have spent time in that world.

Craig Johnson's direction allows each character to be seen as a distinct person, having to work at making connections with others. He allows for the ambiguity often present in assessing a person's motives. Are Claire's ideas about Catherine born of genuine, sisterly concern or a way to conveniently minimize the problem at hand? Is Hal's euphoria over the discovered proof based on the opportunity to fan one final burst of glory on his highly esteemed mentor, or is he ignited by the prospect of lifting his own mantle? And is Catherine really as dysfunctional as Claire believes, or is she just needing a breath before regaining her strength?

A quartet of terrific actors animate each of these characters. Maggie Cramer is excellent as Catherine, fully persuasive as her moods shift from depressed to angry to protective to seductive to hopeful and back again. Coleson Eldredge captures Hal's amalgamation of nerdy mathematician, aspiring cool guy (he plays drums in a terrible rock band), and discouraged striver who fears that at the age of 28 his best work is behind him, with little to show for it. Sarah Furniss is aptly annoying as Claire, especially early on when she tries far too hard to be sensitive to her younger sibling, whose inner life she clearly knows nothing about. Claire becomes more relatable in the course of the play as Furniss conveys the reality that, in Claire's position, a person has to do something, and what are the better options?

Lastly, Patrick Thomas O'Brien is wonderful as Robert, expressing his enthusiasms with panache, and deeply moving when recognizing the toll his illness is taking on him, and his desperate need for his daughter's caregiving. O'Brien paints Robert, in improved health, as every grad student's favorite professor, and a true force to be reckoned with.

Carl Schoenborn's set design creates an aptly austere porch and yard with a proper door into the house on the clapboard exterior wall, as well as a gap in the boards that allows the deceased Robert to pass through like an apparition. Schoenborn's lighting design bathes the space in morning, afternoon, and nighttime angles of sun or star light. Sarah Bauer's costume designs suit the character's to a tee, with a knowing contrast between Catherine's initially sloven look and Claire's well-put-together garb. Aaron Newman's sound design fits the needs of the production well, including an offering of the noise emanating from carousing mathematicians at an after-funeral party.

The play's title cuts two ways: it refers, of course to mathematical proofs, such as the one discovered tucked away in Robert's study, and the splash they can make within the math community. It also refers to what constitutes sufficient proof for us to feel we can proceed with certainty in our lives. What evidence do we need, how much must be based on faith or trust? Auburn wisely makes it unnecessary to be conversant in math to make sense of his meanings.

Proof is that rare bird, a serious play that did very well both critically and commercially, running over two years on Broadway and launching a national tour. Even so, it doesn't come around too often any more. When it does, it is well worth catching, all the more so when mounted with such care and intelligence as you'll find at the Gremlin.

Proof runs through March 30, 2025, at Gremlin Theatre, 550 Vandalia Street, Saint Paul, Minnesota MN. For tickets and information, please visit gremlintheatre.org or call 1-888-71-TICKETS.

Playwright: David Auburn; Director: Craig Johnson; Technical Director, Scenic and Light Designer: Carl Schoenborn; Costume and Prop Design: Sarah Bauer; Sound Design: Aaron Newman; Assistant Director and Dramaturg: Alex Church; Stage Manager: Maren Findlay; Producing Artistic Director: Peter Christian Hansen.

Cast: Maggie Cramer (Catherine), Coleson Eldredge (Hal), Sarah Furniss (Claire), Patrick Thomas O'Brien (Robert).