Congresswoman Geddes from Episode 82 ("The Dinner Party") asks Mary to entertain Johnny Carson, who is visiting Minneapolis. Mary thinks for once she can have a party which is not a disaster. As the gang awaits the celebrity's arrival in Mary's apartment, there is a power failure and no candles or working flashlights are to be found. The guests recall a series of Mary's bad parties through flashbacks. Guest star: Johnny Carson. Valerie Harper and Henry Winkler appear in flashback scenes. Irene Tedrow reprises her role as Congresswomen Margaret Geddes.
