Visiting a client in jail, Marsha comes face-to-face with Sharon Whit, an exact Marsha lookalike. During their consultation, Sharon knocks out Marsha and switches places with her, leaving Marsha trapped in prison while Sharon moves into the Owens' household, not finding George all that attractive. Noting 'Marsha's' increasingly unusual behavior, including cooking edible food, the family soon figures out she's not who she seems to be. In prison, Marsha vehemently protests that she's not Sharon Whit, although her cellmates and the guards ignore her. When Marsha attempts to cheer up a depressed cellmate by suggesting a singalong, their guard is taken hostage, demanding that everyone sing "Do-Re-Me", leading to a song-and-dance number which convinces the guards that Marsha is not Sharon Whit - and she arrives at home just as the family figures out the truth behind the switch - only to awaken and find it was all a dream, caused by her fears of an upcoming test in school.