Under The Rainbow is a comedy set in Los Angeles in 1938. Production of The Wizard of Oz is beginning and actors are getting ready for the filming. Annie Clark (Carrie Fisher) escorts 150 little people, who have been cast as Munchkins, to their hotel and must keep them out of trouble until they begin working on the movie. In New York, Secret Service agent Bruce Thorpe (Chevy Chase) is assigned to protect the Duke (Joseph Maher) and Duchess of Austria (Eve Arden) from assassination attempts as they travel cross-country by train to Los Angeles. Rollo Sweet (Cork Hubbard), a little person from Kansas, has stowed away on the train in a mail sack, determined to get to Los Angeles to start his acting career. Eventually, everyone ends up at the same hotel which soon is bursting with Munchkins, military spies, and royalty. And, like The Wizard of Oz, all is not what it seems to be.