While their elders are away at a wedding in Boston for the weekend, Alan and Nathaniel are trusted to stay on their own. Then Warren, inspired by an article in Life, comes up with an idea for a ""dinner party"" with Katie and her friends ""the Marys,"" and Nathaniel is excluded. But the tables are turned on the boys when Nathaniel gets sick and the girls pay more attention to him than to them.

Nathaniel is upset when Jules and Sophie's cousin Myron, once partners in the hatmaking business, have a falling out at the weekly Friday night poker game and stop speaking to each other. In the meantime, Uncle Joel is helping George and Phyllis get through an income tax audit.

On Grandpa's birthday, Phyllis and George give him and Grandma a gift, a romantic weekend at the Plaza Hotel--an excursion the Bergers consider until Nathaniel contracts chicken pox. Sophie takes over his care with such vigor, overruling all of Phyllis' instructions, that Phyllis feels thrust in the background of her own child's care and her anger precipitates a quarrel between her and her mother. Meanwhile, Benny stakes out an apartment building in hopes of seeing his favorite baseball player, Duke Snider.