Dr. Tess Coleman (Curtis) and her teenage daughter Anna (Lohan) have one thing in common - they don't relate to each other on anything. Not clothes or hair, or men or Anna's rock band aspirations. Nothing. After one particularly explosive Thursday evening, a little mystic mayhem changes their lives. They wake up Friday to the biggest freak-out ever - Tess and Anna are trapped inside each other's body. Literally forced to walk in each other's shoes, they gain respect and understanding for the other's point of view. But Tess's wedding is Saturday, and the two must find a way to switch back. And fast.