The Annual School ragdrive starts Chip off on a scavenger hunt of the neighbourhood. Everytime Miss Pitts looks out the window she sees strange happenings at the Douglas household. She sees Bub outdoors waving a bottle that looks like whiskey,and later, Robbie carrying in a dummy that she thinks is Bub smashed to the nines. Later she goes over to talk to Steve about her concerns, and sees Chip in his bedroom hitting the dummy and when it accidentally falls out of the upstairs window, she faints on the sidewalk.

A Missile launch, sleeping in and Daylight Saving make for an interesting Monday morning. The Douglas household is a chaotic affair of lost indian arrow heads for Chip's turn in show and tell at School, Robbie's missing trumpet and some important lost plans of Steve's that Mike has nearly burned in the incinerator.

Chip begins to think it would be great to be an older brother, so he wishes for a little sister. After the new Hawkins family move into the vacant house across the street, a wild sequence of events results from an improbable case of mistaken identity -- an infant is somehow confused with a leg of lamb left in the boot of Steve's station wagon.

Chip brags to his new playmate that his genius brother Robbie can fix almost anything. Soon Robbie is repairing a Grand Piano and has five minutes to have it fixed before the boy's mother comes in and wants to practise a new tune on it.