“Proof” is the story of Catherine, a gifted young mathematician, as she and her sister Claire, are dealing with the death of their recently deceased father, a brilliant mathematician himself, though a bit unstable. Catherine had given up her college and her plans for the future to return home five years earlier to care for Robert. Hal, a former student of Robert’s, and now a Math Professor himself, is also on the scene. He is seeking any enlightening research in the attic where Robert kept meticulous records of these last five years. Claire simply wants to get Catherine out of the house, for she fears her younger sister is a bit deranged and cannot care for herself. She also wants to sell the house.
What is discovered is a journal of profound importance of a mathematical proof in a desk upstairs. How could he have written such a piece given his condition? Did he write it, or was it the work of his daughter, Catherine? It is one of the major factors that drives this Pulitzer Prize and Tony award winning drama by David Auburn from 2001, which is on the stage at Act II Playhouse this month. Their cast of four give a powerful presentation of Auburn’s play!
It opens with Catherine talking and laughing with her father. We then realize that this is a dream of Catherine’s. There are eight more scenes in this two-act play where we see the struggling relationships between the sisters and, between Catherine and Hal, who develop an attraction for each other. And then, there is the dealing with a parent who was once one of the leading minds in the field of mathematics, but in his last years, was, often confused.
There is also the main substory about the authorship of the newly discovered work. They want to dismiss the idea that a young girl with a half semester of college could have written such a paper.
While the core of the story takes place during the weekend of the funeral for Robert, we learn so much as we actually see Robert in two flashback scenes. I loved Scott Langdon’s portrayal of Robert. It was not one of a crazy, looney man but of a genuine person, a kind person, who is still smart, as he loses his sharp analytical powers.
I loved all the portrayals by the actors. Megan McDermott brings a practical, no-nonsense quality to Claire as she seeks a logical way out of the dilemmas she is confronted with. Adam Howard portrays Hal in a most genuine manner, even though he has geekish qualities. We love the brief romance between him and Catherine even though we have trouble with his disbelief in the fact that she, a woman, is the author of the new proof.
And I can’t say enough about Jenna Kuerzi’s Catherine. She is portraying a woman who has had no life for five years outside of caring for her father. She has no friends. She has gone nowhere. She’s a bit of a geek herself. And she constantly worries that she is so much like her father that she will eventually inherit his mental illness. But she is so real that we soon identify with her and feel her struggles.
Director Kate Brennan has given us a play that won many awards but can easily be presented superficially. There is nothing superficial about this staging. She has found the perfect cast, and we can see why it won so many awards in her masterful direction of this powerful drama.
An afterthought: “Proof” is reopening on Broadway this Spring for 16 weeks where the tickets begin at $144. At Act II, they start at $35, and I can’t imagine a production better than theirs.
“Proof” by David Auburn at Act II Playhouse, 56 E. Butler Avenue., Ambler, PA 19002, 215-654-0200, act2.org thru March 1,, 2026