Moonshine River is the first episode of the 24th season. The episode was also dedicated to Andy Williams, who died five days before the episode aired due to bladder cancer.
After Bart realizes that his relationships didn't last long he plans to visit all of his ex-girlfriends for a second chance. After being rejected by them all he goes to see Mary Spuckler to learn that she moved to New York. Finding Mary his last chance at love, the family travels to New York City.
During a dance following a disastrous joint celebration of the Springfield Grand Prix (a car-race tournament) and the final stage of the Tour de Springfield (a cyclist competition), Bart makes fun of Lisa and Milhouse while they were dancing. Lisa opposes that she is with someone who likes her, to which Bart replies of how he has had relationships before. However, Lisa counters that he never had a relationship that lasted long. Seeing that Lisa is right, he chooses to visit his girlfriends.
At the Spuckler house, Bart asks Cletus if she is here, Cletus and Brandine to inform Bart and Milhouse that Mary ran away after being engaged. Dubya Spuckler then informs them that Mary is at New York City. Bart then asks the family if they can go to New York, and after some thinking, they agree to go. Bart and Homer search for Mary, and just when he thinks that he will never find Mary, he comes across her and sees that her appearance changed. As Bart and Mary go around the city and chat, Mary sings a song for Bart while playing the guitar. She then admits her love for Bart. However, before the two get a chance to kiss, Cletus suddenly arrives, saying he will bring Mary back.
As Cletus and the family are occupied, Mary reveals to Bart that she is leaving them again. After kissing Bart, Mary says goodbye and leaves on a train. When Cletus sees she is gone, he orders Bart to reveal what happened. Bart refuses, as he says that Mary is proof that a girl will like him. Cletus then realizes that it is time to let Mary go. The family and Cletus go back to Springfield, and during the ride, Cletus gives Bart a picture of Mary so he can remember her.
Simultaneous to Bart and Homer's search for Mary, Lisa and Marge try to find some entertainment. They eventually go to a show of Romeo and Juliet, only to realize that the cast has quit due to a feud. Marge and Lisa choose to do stage their own play of Romeo and Juliet, only for them to get arrested. During the train ride back to Springfield, Lisa becomes outraged to see bad reviews of her show in the paper but calms down to see that the critics like her.