A film detective believes he actually has the skills to solve a real life case. Bill Martin's (Jack Oakie) boasts irritate the real detectives of the Los Angeles police, as well as studio publicist Mary Strand (Ann Sothern), who loves Bill but doesn't appreciate the actor's arrogance.
A mysterious killer known as the "Poison Pen" decides to murder Bill, annoyed with his last movie. Bill and Mary go to amateur sleuth Professor Herman (Eduardo Ciannelli) for advice, unaware that the professor and the murderer are one and the same.
By mistake, film co-star Ralph Waring (Bradley Page) is killed by the Poison Pen, and stand-in Larry Frank (Alan Bruce) is suspected of the crime. To save Bill from the killer and from himself, Mary arranges for him to be locked up, but the gullible Bill gets Professor Herman to bail him out of jail. Mary and the cops come to his rescue just in time.
^Schallert, Edwin (Nov 14, 1936). "HAL MOHR TO DIRECT "CLASS PROPHECY;" JACK OAKIE CAST AS "SUPER SLEUTH": Bernadene Hayes Tested for "Stella Dallas;" Beauties in McLaglen Film". Los Angeles Times. p. 10.
