Pulitzer Prize winner, Proof, is a highly engaging drama set in Chicago. Catherine, a young woman who has spent years caring for her brilliant but unstable father, Robert, must deal not only with his death but with the arrival of her estranged sister, Claire, and the attentions of Hal, a former student of her father's who hopes to find valuable mathematical solutions in the 103 notebooks Robert left behind. Catherine struggles to solve the most perplexing problem of all: how much of her father's madness - or genius - will she inherit?