Somebody is selling songs for two recording companies, simultaneously. The owner of one of them hires a detective to find out the swindler's identity. But the private-eye is clumsy, and messes things up even more.
A woman impressed by news reports about flying saucers, gets hit on the head by a vase, passes out and dreams that she is the 'Queen of Mars', from where she sends an expedition to Earth in order to bring back Rio's Carnaval to the planet.