Jack Sadelstein (Adam Sandler) is on top of his game, and has every reason to be thankful: he has a beautiful wife (Katie Holmes), great kids, a gorgeous house in L.A., and a successful job as an advertising executive. Even still, Jack always dreads the coming of Thanksgiving because for him, the holiday only means one thing: a visit from his needy, annoying, passive-aggressive, neurotic, identical twin sister, Jill (also played by Sandler).