Winner of both the Pulitzer Prize and Tony Award for best play, "Proof" is an often-funny, surprising thriller that examines brilliance, illness and legacy. Catherine’s recent life has been spent taking care of her father, a mathematician whose genius bowed to madness in his final years. On the weekend of his funeral, she becomes undone by the visit of her estranged sister, the budding romance of a graduate student, and the mystery of what, exactly, did she inherit from her father?