Clara Corbin is writer who writes soap opera serials for the radio. Now the plot of one of her shows, My Sister's Husband, is actually happening in real life. She gets a note saying "If you don't stop writing about Larry and me I'll kill you" and another one saying, "take me out of your script if you want to keep on writing". She bases her serial on her sister and brother-in-law but mostly makes the plots up. When she writes about her brother-in-law having an affair could she have accidentally stumbled on a true story. Clara fears that the other woman in real life is going to murder her and hires Nick Carter to investigate.