In the episode, Ricky Ricardo (Desi Arnaz) learns from his stage manager Jerry, that he lost his dancer Joanne, who has last the act. Ricky tells him to roundup some replacement dancers for the following morning, who can all wear the size 12 (modern 4-6) to fit in the former dancer's costume. Lucy Ricardo (Lucille Ball) begs to audition, and Ricky agrees.
The next morning, Lucy and Ethel Mertz (Vivian Vance) show up for her audition, and she finds herself in the company of four other hopefuls. Lucy taps Dancer #1 (brunette) on the shoulder and asks if "this is where Ricky Ricardo is auditioning girls for the dance". The gorgeous brunette looks Lucy up and down, and responds, "Yeah Honey, but if I'd known he wanted older women, I would have brought my mother". Ethel told Lucy not to pay any attention to her. Lucy then walks over and sits next to Dancer #2 (blonde), who leans over and tell's Lucy, "Can I give you a tip? I've known Ricky Ricardo for a long time. You're not his type".
Not discouraged by these catty comments, Lucy rolls up her pants to display her legs, unbuttons her shirt, hikes up her midriff, and then lowers her neck line of her shirt to show her bare shoulders.
Ricky walks in and tells all the girls to line up. Lucy is at first not on the lineup, since the girls have crowded her out, but she pushes herself in to make room. Ricky has them start with a time-step, which Lucy struggles to keep up with the other girls. Ricky asks if all of the girls can fit into a 12 costume, since that is what the last dancer wore. All the girls agree, but Ricky is skeptical of Lucy, and asks her to approach her. Ricky asks her to go try on the costume in the back dressing room. When Lucy came out of the dressing room, she has clearly shredded the outfit in order to get it on over her mid-section. The outfit consists of a green dress, feathered hat, and sequined purse. The other girls begin snickering, laughing and pointing at Lucy. Ricky tells Lucy that she needs to go take the costume off, and that he will call her if they need her. However, Lucy tells him that she will fix the costume, and then pleads with him, that if she could fit into the outfit by Saturday, would he consider allowing her to have the part. Ricky agrees, mostly just to get rid of her. Lucy makes the comment to Ethel, that she is "going to get rid of this extra weight if she has to chop it off with a cleaver". Lucy spends the rest of the episode trying everything she can to lose the twelve pounds in the next five days.
On the night of the performance, Ricky is singing and dancing at the club. The cue comes during the Sally Sweet portion of the Cuban Pete number, and the dancer comes out. Much to Ricky's surprise, Lucy comes out. This obviously was not expected, but Lucy makes the most of her opportunity. and the crowd loves the performance.After the episode, Lucy is seen on a rolling bed with doctors all around her. Lucy asks if she will be able to continue the act, but Ricky tells her no, and that the doctors have found her severly malnourshed. Before the doctors can roll her away, she turns to Ethel and hands her a key and points to the nearby janitors closet. After Lucy is rolled away, Ethel unlocks the door, and peeks in. She is disgusted, and then continues to open up the door and walk away. The crowd is privy to the Dancer #1 (brunette) who had mocked Lucy in the auditions, sitting in the janitors sink. Her body is shrowded in a burlap sack, tied at the ankles, with her legs dangling over the edge of the sink. Her hands are tied behind her, and she is gagged with a white cloth over her mouth so she is not able to talk. The dancer is left struggling in the sink, and with no help in sight, as the series credits with the heart closes in. Questions are left to the audience to figure out. Was the dancer knocked out and tied up in order to get her costume? How did Lucy learn the dance steps, did she have the girl teach the dance moves to her, or did she torture her to have her do it? Did anyone ever get the young lady out of this predicament? What kind of effect did this have on the girls career? Obviously, she lost the opportunity that this gig would have provided her. Was she able to replace Lucy in the subsequent shows, or did this have psychological effects on her. Anyway, all of these questions were left unanswered for many to ponder.