The Teen-Agers are down in the dumps: their football team faces almost-certain defeat, the school paper might need to suspend publication because circulation is so low, and the principal intends to replace student performers with professionals.

Joe Cobb is suffering through a toothache as well as having to babysit his little brother Rupert who won't stop crying. Every effort to calm Rupert is undone by an immediate commotion to wake him up. Joe rocks him to sleep, but then the neighbor starts playing his bass fiddle. Joe then rocks the cradle so hard it falls apart, and he trips and stumbles moving Rupert to the baby carriage, which subsequently rolls down hill through traffic with Rupert and a neighbor's monkey enjoying the ride.

A Marine Sergeant wounded in overseas combat requires an operation, and the Navy psychiatrist recommends that ‘Sarge’ be given a few weeks’ rest before hospitalization. Through the Dean of San Juan Junior College, Sarge enters on a temporary basis. Meanwhile, the Teen-Agers are rehearsing a show and Freddie's worried as they have no band.

When teen heartthrob Frankie Troy disappears, high schooler Freddie Trimble–a dead ringer for the crooner–is singled out by his so-called friends as the radio star. As hijinks ensue, things worsen when Troy's wife and newborn arrive.