Gwyneth Paltrow, who won an Oscar for her performance in director John Madden's SHAKESPEARE IN LOVE, teams up again with Madden in PROOF, a poignant drama based on David Auburn's Pulitzer Prize-winning play. Paltrow lights up the screen as Catherine, a young woman who has given up a seemingly bright future in order to take care of her ailing father, Robert (Anthony Hopkins), a formerly brilliant mathematician who went crazy. After he dies, Catherine's closed-off world is invaded by Hal (Jake Gyllenhaal), a young mathematician who worshipped Robert, and Claire (Hope Davis), her successful sister who fears that Catherine is too much like their father--a talented, supremely intelligent person with severe mental problems. During the last years of his life, Robert filled 103 notebooks with his writings, but one of them, written during a brief period of lucidity, could turn the math world on its head, while also threatening Catherine's already wavering sanity. Auburn co-wrote the screenplay with Rebecca Miller (PERSONAL VELOCITY, THE BALLAD OF JACK AND ROSE), taking it off the stage, setting it in and around Chicago, and breathing new life into the story, along with Stephen Warbeck's compelling score and plenty of outstanding acting, particularly by the glowing Paltrow and the earnest Gyllenhaal.