“The Lars Affair” marks a transition point for The Mary Tyler Moore Show. The first episode of the fourth season introduces the legendary Betty White as Sue Ann Nivens, the Happy Homemaker (who is also a happy homewrecker and a proto-Martha Stewart boss bitch). The show was about to lose Valerie Harper as Rhoda, Mary’s caustic best friend, who was planning her own spinoff. The loss could have, and should have, been devastating. The addition of White eased the blow significantly.

This episode belongs in the pantheon of great character introductions. Sue Ann is having an affair with Lars, the husband of Cloris Leachman’s equally indelible power-housewife Phyllis. Sue Ann refuses to apologize, even when confronted on her cooking-show set while making a soufflé. The resulting showdown between White and Leachman is hall-of-fame level.