Though polar opposites, Mary and Elizabeth are as close as can be--until the night Elizabeth makes an irrevocable mistake and leaves Mary to take the blame. Years later, Elizabeth seems to have forgotten Mary exists. Mary hasn't forgotten her. She follows Elizabeth's every move online, obsessed with paying her back for the betrayal that cost Mary her dreams. Now Mary has found a way to switch bodies with Elizabeth, and she's got a plan to steal her charmed life. Her career. Her looks. Her husband. They do say living well is the best revenge. Or is it? The more Mary uncovers about Elizabeth's life, the more she realizes she may have made a deadly mistake. And she'll need the help of her worst enemy to stay alive.