Rio Rita is a 1942 comedy film starring Abbott and Costello. It was based upon the 1927 Flo Ziegfeld Broadway musical, which was previously made into a 1929 film also titled Rio Rita that starred the comedy team of Wheeler & Woolsey. Kathryn Grayson (in her first starring picture) and John Carroll replace the 1929 version's Bebe Daniels and John Boles.
Nazi spies have infiltrated the Hotel Vista del Rio, a resort on the Mexican border. They plan to use a radio broadcast by a famous guest, Ricardo Montera (John Carroll), to transmit coded messages to their cohorts. Doc (Bud Abbott) and Wishy (Lou Costello) are stowaways in Montera's car, who steal a basket of "apples" that turn out being miniature radios used by the spies. Rita Winslow (Kathryn Grayson), the hotel's owner and childhood sweetheart of Montera, hire Doc and Wishy as house detectives, who discover the Nazi codebook and give it to Montera. They are then kidnapped by the spies, and left in a room with a bomb set to explode, but manage to escape while Wishy plants the bomb in the pocket of one of the culprits. Meanwhile, the broadcast has already begun and Montera, refusing to participate in treason, fights the spies until the Texas Rangers arrive. The spies' escape by car is thwarted when the planted bomb finally explodes.