In Los Angeles, Betty Boop works as a waitress and her friends Koko and Bimbo in the kitchen of a dinning place, which is permanently crowded. The greatest attraction for clients is Betty Boop singing, while dreaming to be a Hollywood star. When Betty and her friends accidentally break some dishware, they are fired by the owner. However, the private eyes Sam Slade hires the team to help him in a security work in a party in the house of the famous star Lola Daville, whose secretary Miss Green has just hired him for the protection of a valuable necklace. When the jewel is stolen in the party, Betty Boop becomes the suspect number one, since the criminal left his gun in her hands during a blackout, and Sam is unable to prove her innocence wounded in the hospital. Betty Boop is rescued from the police station by Koko and Bimbo, and the trio investigates who could be the thief. Meanwhile, the dinner place is completely empty, since clients do not have the show of Betty Boop anymore.