A stagestruck young actor accidentally receives somebody else's invitation to test in Hollywood.

Amateur actor Harold Hall from Littleton, Kansas, mistakenly sends another man's photo to Planet Studios in Hollywood and is offered a screen test. Once in Hollywood, the naïve and clumsy Harold is asked to be an extra on a film set, then bumbles the job, but falls in love with the leading character of the film, the "Spanish lady," played by Mary Sears. Harold then reports to L. J. O'Brien of Planet Films who, expecting the handsome man of the photo, angrily dismisses Harold, while insisting his staff screen test "Harold Hall." After failing the test miserably, Harold is caught in a rainstorm with Mary, whom he does not know is the Spanish lady. By the time Harold and Mary arrive at her apartment, soaked, she has nicknamed him "Trouble," pleased to meet a man who has not made a pass at her upon their first meeting. Later, dressed as the Spanish lady, Mary coaxes Harold into giving her his fraternity pin, although she knows he told Mary it was reserved for the girl. In her own clothes, Mary then accuses Harold of being a cad, but they kiss and he promises to get the pin back. Mary continues the façade until poor Harold kisses the Spanish lady, after which Mary writes a note on the back of an invitation to a Hollywood party asking never to see him again. Harold reads the wrong side of Mary's card and goes to the party believing he is Mary's guest. There he causes a great disturbance when he mistakenly dons a magician's coat in the washroom and numerous gags are released on the dance floor, including a litter of mice and a bunny. When the magician finally discovers who is wearing his coat, Harold is thrown out of the party. Later Mary reveals her identity to Harold behind the costume of the Spanish lady, and her drunken suitor Vance, seeing Harold on the set, knocks him out in a basket. Harold then wakes up during the film's shooting and continues to fight Vance while the set is flooded for the film's climax. Meanwhile, with the cameras still rolling, the film's producer, Mr. Kitterman, walks on the set and, finding Harold unbelievably funny, offers him a contract. Harold assures Mary, however, that his fight with Vance was for real, and they are reconciled.