"Proof" is the compelling story of an enigmatic young woman haunted by her father’s past and the shadow of her own future, exploring the links between genius and madness, the tender relationships between fathers and daughters and the nature of truth and family.

On the eve of her twenty-seventh birthday, Catherine (Paltrow), a young woman who has spent years caring for her brilliant but unstable father, a mathematical genius named Robert (Hopkins), must deal not only with the arrival of her estranged sister, Claire (Davis), but also with the attentions of Hal (Gyllenhaal), a former student of her father’s who hopes to find valuable work in the 103 notebooks of Robert’s.