Sal is the proprietor of Johnny 50's Diner, a retro-themed diner that Stan loves to eat at during his morning walk, although Stan constantly refers to him as Johnny instead of his correct name.
Stan forces Hayley to accompany him on one morning walk to discuss her lack of ambition. As the only thing he'll eat there is toast, Stan brings his own food for Sal to cook for him. The lack of paying customers from Stan and other people have forced Sal to consider closing the diner. Determined to save the restaurant, Stan decides to get people interested in the '50s again.
However, motivated by Stan, Hayley discovers that Sub Hub is looking to expand in the gaslamp district where the diner is located. When she informs them of the diner's pending closure, they offer to make her manager of the new location. Stan feels betrayed when he discovers that not only is Hayley working against him, but that he has only 48 hours to save the diner. His efforts to bring the fifties back to Langley almost fall flat, but just as Hayley begins to have second thoughts about her potential victory, his blaming her for his setbacks angers her, and she accepts his challenge.
To spark a big interest, Stan injures a teenager in a 50s-style knife fight. As the crowd gathers, he manages to convince them that it's all just normal life from the 50s. With the citizens back on his side, Sub Hub abandons their pursuit of the diner, but Hayley, losing her chance of promotion, decides to challenge him to a drag race using vintage cars. As they race, Stan listens to a song that Roger recorded back in the 1950s and that he used to listen to when taking Hayley that the diner in her younger years, carving their initials in a table. Unable to get her attention to stop the race, his attempt to fix the situation Fonzie-style results in the steering wheel coming off when he hits it with his fist. He's ejected from the car, which then crashes into the diner. As Sal and the crowd celebrate the return of interest in the 1950s, the diner goes up in flames, Hayley, realizing that Stan may have brain damage, offers to take him to the hospital, but not before they get a look at the table they used to share together.