To her dismay, Lucy finds out that she's put on 22 pounds since marrying Ricky. Complications arise when one of the girls in Ricky's new show quits, making a vacancy for a dancer who can wear a size twelve costume. At the auditions the next morning, Lucy tricks Ricky into saying that if she loses enough weight (12 pounds) in four days, then she can be in the show. Thus, she starves and exercises, with Ethel as her coach. In one funny scene, she tries to steal food from the Mertzes' dog Butch, because she is so hungry! She finally resorts to using a steam cabinet, and manages to get down to the required 120 pounds. At the end, Lucy and Ricky perform "Cuban Pete/Sally Sweet." She's a hit, but at the end she collapses, suffering from malnutrition.