Cookie is born, producing unmitigated joy in the Bumstead household. Adding to the chaos a new baby always creates is the appearance of Hans Conried as a cynical author who becomes caught up in the Bumstead lifestyle.

Baby Dumpling, the six-year-old son of Blondie and Dagwood Bumstead disappears from sight during his first day at school. While Dagwood frantically combs the city in search of the boy, Baby Dumpling spents a nice, safe afternoon with poor little rich girl Melinda Mason, who with her new playmate's help arises from her sickbed to walk across the room for the first time in months.

The Bumstead family is off to see relatives in the country when Blondie runs into Charlie and Millie, an eloping couple needing her help.

Dagwood wants to join the trout club and Blondie wants a fur coat. Jealousy reigns when Dag's old girlfriend Joan shows up, but nothing else matters when a drawing at the movie theatre provides money for the coat.

Mr. Dithers invites the Bumsteads on a South American cruise. Somehow Dagwood winds up as the female drummer in the ship's band, while Penny Singleton gets to show off her Broadway background in some lively musical numbers.

Blondie and Dagwood are about to celebrate their fifth wedding anniversary but this happy occasion is marred when the bumbling Dagwood gets himself involved in a scheme that is promising financial ruin for the Bumstead family.