Unfolding over an autumn weekend in Chicago, Proof depicts the story of Catherine, a fragile young woman who is in the process of burying her father, a once great mathematician whose final years were spent in madness. Having sacrificed her own studies to care for him, Catherine, disheveled, bitter, and immobilized by depression, is both fearful and compelled to fulfill her father's legacy. Catherine is courted by Hal, a shy but insistent, former student of her father's who has been going through the dead mathematician's notebooks hoping to find an unpublished revelation. As Catherine and Hal's mutual affection waxes and wanes under the watchful eye of Catherine's sister, Claire, the mystery surrounding the authorship of an important mathematical proof is revealed. At once an intimate back porch drama and a compelling detective story, this show provides an intimate, often funny, examination of the world of higher mathematics, human relationships, and the painful joy that accompanies genius.