The Simpsons go to see if they would like to take any of the classes at the YMCA. Homer tries out the basketball class but he tears the ACL in his knee. He can't go to work while he recovers from surgery. He is bored at home. He tries unsuccessfully to breed the dog and the cat to each other, and then Homer takes care of Rod and Todd one evening. When he finds that he is pretty good at it, he starts a daycare center. He still neglects Bart and Lisa, making them jealous. He becomes eligible for a Good Guy award for his service to the community. A film crew follows him as he does good deeds. Bart and Lisa devise a plan to show the world that he is a neglectful father. At the awards ceremony, they show home movies of him. When he ends up choking Bart, everyone is outraged. Homer flees the ceremony with the kids in a stolen car. The police catch him and later he apologizes to Bart and Lisa for his behavior.

Bobby passes himself off as a high school student (explaining his height by claiming that he suffers from a kidney condition), and gets caught up in the school's attempt to get the band No Doubt to play at their prom. Meanwhile, Dale creates the perfect outhouse, the Port-a-Gribble the envy of all the neighbors.

Mulder and Doggett join forces to investigate the arson attack on a genetics lab where one of the doctors suspected of experimenting with alien impregnation is killed. They encounter Billy Miles, who has been changed into an alien replicant after his recent abduction and is attempting to erase evidence of the tests. When a woman helping Scully out at home is found to be a part of the conspiracy, the agents, along with Monica Reyes and Alex Krycek, know they must protect Scully and her baby from Billy Miles and get her out of the city.

Tony must lay down the law with a distraught Gloria when she threatens to expose their affair to his family.
Jackie seeks some advice from Ralphie and decides to pull a daring heist to prove himself, but his plans go horribly wrong when blood is spilled.
Carmela takes an emotional dive and suddenly becomes interested in real estate.

While babysitting both Trinity and Mrs. Peterson's dog, Ricky accidentally gets shot and the dog devours a tray of hash brownies. A vet treats both the dog and Ricky. In order to pay the vet, Ricky and Julian must repossess a lawn tractor owned by a former patient who hasn't paid the vet's bill. The Boys successfully recover the tractor -- but not before Ricky gets shot for the second time that day.

Fry falls in love with Liubot (guest star Lucy Liu, 'Ally McBeal'), a virtual humanoid downloaded from a computer. Disapproving of Fry's affair with a virtual woman, Bender and Leela steal the original head of Lucy Liu from the internet company, Nappster.com, where she is being held against her will. Seeking revenge, the Nappsters unleash a mob of illegal Lucy Liu downloads to take over the city.