Moe Szyslak becomes lonely and decides to commit suicide by jumping off a bridge. However, he inadvertently saves Maggie Simpson when she is sent flying from the Simpsons' car window and into his arms. He starts playing with Maggie and becomes attached to her, telling her the story of The Godfather. Homer and Marge become upset about how much time Moe is spending with Maggie and forbid him from seeing her again. One night, Maggie wakes up and hears Fat Tony and the Springfield Mafia outside the house and decides to follow them. When Homer and Marge find her missing, they automatically assume that Moe kidnapped her. When Moe is told that Maggie is missing, his request to help find her is granted by Homer. Maggie follows the mobsters to Luigi's restaurant, where Fat Tony's gang gets into a gun battle with a rival family. Homer, Marge and Moe track Maggie down and Moe decides to go inside and save Maggie. After Moe saves Maggie's life, Homer allows the two to spend more time together.

Homer and Marge recall the story of their first kiss at a summer camp when they were children—an event which was not all happy, as Homer (unwillingly) betrayed Marge by standing her up on their second date.

Springfield legalizes same-sex marriage to increase tourism. After becoming a minister, Homer starts to wed people to make money. Meanwhile, Marge's sister Patty comes out as a lesbian and reveals that she is going to marry a woman named Veronica.

Working through their checklists of things to do before summer ends, Lisa gets the family to go a museum. At the Springfield Museum of Natural History there is an exhibit Lisa is excited to see on Women’s History turns into an exhibit on the history of weapons, which excites Homer and Bart. When Flanders sees the exhibit of evolution and another that mocks creationism, he raises an alarm. Reverend Lovejoy gets Skinner to have creationism taught in school. Lisa is the only one who holds onto the scientific theory. She brings the topic up at the town meeting and the town votes to teach only one theory, creationism. Lisa decides to hold her own class on evolution, until she is arrested. The ACLU gives her a lawyer who is up against a slick Southern lawyer, but ultimately it’s a family member that is a key to her defense.

After a celebrity scandal is accidentally captured in a family photo, Homer decides to become a paparazzo.

Marge goes online for the first time and becomes obsessed with a role-playing game that Bart and many of their neighbors are playing. Meanwhile, Lisa develops her own obsession--for soccer--and Homer becomes a referee.

Homer loses his memory--and his family--when he drinks Moe's most potent libation, the Forget-Me-Shot, in an episode that spoofs "Eternal Sunshine of the Spotless Mind" and "It's a Wonderful Life."

When Marge learns Springfield Elementary is the worst school in the state, she and Homer rent an apartment in the upscale Waverly Hills school district so Bart and Lisa can attend a better school. Meanwhile, Homer moves into the rented Waverly Hills apartment and gets used to the bachelor lifestyle.

In this futuristic holiday episode, Bart is a deadbeat dad living in Springfield Elementary (which is now an apartment complex instead of a school) with Principal Skinner as his landlord. Meanwhile, a pregnant Maggie goes into labor during a family dinner.

Lisa creates her own social networking service, SpringFace, and subsequently makes everyone addicted to the internet. Meanwhile, Patty and Selma challenge the Winklevoss twins at the 2012 Summer Olympics.

Homer's behavior once again lands him in hot water with Marge and he needs to fathom a way to save his marriage, while a dose of "A Streetcar Named Desire" drives Milhouse to affect a Marlon Brando-esque bad-boy demeanor in an effort to impress Lisa.

Homer becomes annoyed with movie theaters, so Bart teaches him how to download movies illegally. Homer is delighted with his discovery of free movies until he's caught for piracy. Deputy Director Gratman, the FBI's anti-piracy boss, is tasked with hunting down Homer, who stands accused of illegally downloading a film.

Set in the future, Homer has a new clone for every time he dies. Lisa is married to a zombie version of Milhouse, while Bart deals with custody issues with his ex-wife, Jenda. Each defines what love means to them.

The Planet Express crew come to present-day Springfield to prevent the Simpsons from destroying the future.

Homer is diagnosed with narcolepsy, but instead of returning home with his prescription medication, he returns home drunk. He and Marge visit a marriage counselor and have a trial separation, during which Homer begins dating a 20-something.

Upon learning that their father really died of lung cancer, Selma and Patty agree to quit smoking. When Selma relapses, an angry Patty moves in with Marge and Homer.

Homer recalls a tense family vacation to the Grand Canyon with the Flanders family. At first, the Flanders’ perfection puts the families at odds, but when they get stranded and Ned and Bart go for help, the families finally bond.

Mr. Burns hires the Simpsons, except Homer, to be his virtual family; Homer becomes best friends with the girl next door.

After a successful animal rights campaign, all dogs in Springfield are allowed to go where they want and do what they want. Pack mentality quickly kicks in and the dogs of Springfield assert their dominance by threatening the people.

Bart falls into a coma after being struck by lightening.

The 666th episode of the Simpsons parodies the Omen and Stranger Things, not to mention a little Crazy Rich Aliens.

Marge recruits Chrissy Teigen and John Legend for an education-based proposal.

When Marge implements a screen time limit for the family, she realizes that she is the one addicted.

Lisa makes a shocking college decision, wounding Marge. It leads to a very surprising place.

When Marge and Lisa start a charity together, Marge is seduced by the money and prestige of Big Charity fundraising.

Homer loses his mind over tipping culture run amok.