The story takes place at a summer theater in the Berkshire Mountains, where heroine Joan Barry (Carol Bruce) is staging a Broadway-bound musical comedy. Only one problem: two guest stars are shot and killed on two successive evenings, right in front of the audience. Hoping to solve the mystery, detective William Demarest demands that everyone -- actors and theatergoers alike -- return the following weekend to restage the show. But with no major performer willing to assume the fatal guest-star slot, Joan is forced to hire the Three Jolly Jesters (Al, Harry and Jimmy Ritz), Manhattan washroom attendants with showbiz aspirations.
J. D. Forbes, head of the almost-bankrupt Four Star Studios in Hollywood contacts band leader Kay Kyser, who puts on a radio and-live theatre program called "The Kollege of Musical Knowledge," to appear in films. When manager Chuck Deems gets the studio offer, he and band members Ginny Simms, Sully Mason, Ish Kabiddle, Harry Babbitt and the others are all fired up at the prospect of going to Hollywood and working in the movies, but band-leader Kay is all against it and says his old grandmother has told him to stay in his own back yard, but he relents. Once there, Stacey Delmore, a Four Star associate producer left in charge of the studio while Forbes is out of town, discovers that the screenplay writers have prepared a script that has Kay Kyser playing a glamorous lover in an exotic European setting.
