When Homer rescues Mark Hamill and Mayor Quimby from a brawl in a sci-fi convention, he is appointed the mayor's new bodyguard. But after convincing Quimby that he needs to prevent Fat Tony's mob from selling rats milk to the town's schools, the mayor's life is placed in jeopardy.
The family attends the Bi-Monthly Sci-fi Convention, featuring an appearance by Mark Hamill. Hamill tries to promote Sprint, but only causes a massive nerd riot. Homer fights through the mob of nerds and leads Mayor Quimby and Mark Hamill to safety. The mayor fires his bodyguards, who were too busy looking at clouds outside instead of protecting their boss, and appoints Homer as his new bodyguard, citing he would "make a better bodyguard" than them.
While enjoying the advantages of being a bodyguard Homer discovers that Fat Tony's mafia is milking rats in order to sell the milk to ignorant investors. He finds out that their main client is Springfield Elementary. He visits the school and gags as he watches the students around him drink the carton after carton oblivious to the fact that the milk comes from rats and prevents Bart from drink his own carton. Homer demands that the mayor put an end to it even though Mayor Quimby knows that Fat Tony will come after him. Homer tries to ease his troubles by taking him out to eat at the Springfield Dinner Theater, where Guys and Dolls is being performed. Fat Tony and Louie are also there. Homer fights off Louie, but Fat Tony manages to beat Mayor Quimby anyway and send him to the hospital.While coping with defeat, Mark cheers Homer up by saying that he is still a good bodyguard and the episode finishes with Homer once again fighting off an outraged crowd while carrying Mark to safety.
Empire magazine named Hamill's appearance in the episode as the tenth best film gag in the show, saying: “As a rule, celebrity cameos are rubbish, but good sport Hamill is hilarious when singing 'Luke, be a Jedi tonight' in a production of Guys and Dolls, and makes this list for urging bodyguard Homer to 'use the forks'.” Eric Goldman, Dan Iverson and Brian Zoromski of IGN marked Hamill's guest appearance second on a list of Top 25 Simpsons Guest appearances.