Divorced working mother Christine Campbell (series star JULIA LOUIS-DREYFUS) owns a women's 30-minute workout gym, successfully juggling the daily stresses of motherhood and her business. Her 8-year-old son, Ritchie (series star TREVOR GAGNON), has just been accepted into a posh private school frequented by two snooty stay-at-home moms, Marly (series star TRICIA O'KELLEY) and Lindsay (series star ALEX KAPP HORNER). Christine's twentysomething slacker brother, Matthew (series star HAMISH LINKLATER), lives with her and also serves as Ritchie's babysitter. Christine gets along with her charming ex-husband, Richard (series star CLARK GREGG), even better than when they were married, but her life gets a lot more complicated when she meets Richard's new girlfriend: a nice, young, impossible-to-hate woman also named Christine (series star EMILY RUTHERFURD)...the "new" Christine.