From the moment she glimpses her idol at the stage door, Catherine Moreau is determined to take the reins of power away from the great actress Adeline Margaux. Catherine maneuvers her way into Adeline's role, becomes a sensation and even causes turmoil in the lives of Adeline's director boyfriend, her playwright and his wife. Only the cynical drama critic sees through Catherine, admiring her audacity and perfect pattern of deceit.