Mental illness, sisterly love (or not) and a budding romance come together in a not-so-neat package in “Proof” by David Auburn now onstage at Act II Playhouse through March 1. Parents, take heed in what you ask of your children, as science tells us today, they become adults after reaching 25; as the play so pointedly begins with a celebration of Catherine’s 25th birthday.
Megan McDermott, Adam Howard, Jenna Kuerzi in a scene from “Proof” at Act II Playhouse. Photo by Mark Garvin.
Loving math is a bonus, but the play makes the references to math accessible to all. The action of the play is set outside in the yard of the family home in Chicago.
Act II’s strong cast features Jenna Keurzi as Catherine. Megan McDermott as her sister Claire, Scott Langdon as Robert and Adam Howard is Hal, Robert’s student.
Act II’s set design by Adam Riggar features a backdrop diorama which could be interpreted as the pages of the mathematical works created by father and daughter, or the clouds of time slowly but surely moving.
The play is two hours long with a fifteen intermission, during which we were introduced to the music of Cat Power. Come early and find parking and have a lovely dinner at the many choices within minutes of walking to the Act2 Playhouse, and enjoy a night of solid theatre directed by Kate Brennan.
If You Go
The production closes Sunday, March 1, 2026.
Run Time: 2 Hours with a 15 minute intermission.
Ticket prices start at $35 and are available online at act2.org, by calling the Act II Box Office at 215-654-0200, or in-person at the Box Office at 56 E. Butler Ave., Ambler, PA. The Box Office is open Mon-Sat, 2 p.m. – 6 p.m. Student tickets are $15 and group discounts are available.