In one of his rare performances without Bud Abbott, Lou Costello plays a delivery boy who invents a machine which turns his girlfriend into a giantess.

Gerry and Tom Jeffers are finding married life hard. Tom is an inventor/ architect and there is little money for them to live on. They are about to be thrown out of their apartment when Gerry meets rich businessman being shown around as a prospective tenant. He gives Gerry $700 to start life afresh but Tom refuses to believe her story and they quarrel. Gerry decides the marriage is over and heads to Palm Beach for a quick divorce but Tom has plans to stop her.

Danny O’Neill and Hank Taylor are rival trumpeters with the Perennials, a college band, and both men are still attending college by failing their exams seven years in a row. In the midst of a performance, Danny spies Ellen Miller who ends up being made band manager. Both men compete for her affections while trying to get the other one fired.