In 1990s Pittsburgh, a medicine peddler starts a relationship with a young woman suffering from Parkinson's disease.

The story of Linda Lovelace, who is used and abused by the porn industry at the behest of her coercive husband before taking control of her life.

While performing in Springfield, the band Green Day perishes when the lake's pollution dissolves their barge, following an audience revolt after frontman Billie Joe Armstrong proposes an environmental discussion. At their memorial, Grampa Simpson foresees the destruction of the town, but only Marge takes this seriously. Later that day, Homer dares Bart to skateboard naked to Krusty Burger and Bart ends up arrested. Bart considers their neighbor Ned Flanders a better father after Homer refuses to take responsibility for the incident. Meanwhile, Lisa and her new friend convince the entire town to clean their lake.

Two years after the events of the first film, Larry Daley, former night guard at the American Museum of Natural History, now runs his own direct response television company that sells inventions based on his experiences. He travels to the museum, discovering most of the exhibits will be moved to the Federal Archives at the Smithsonian Institution and replaced with holographic information providers. The Tablet of Ahkmenrah is to remain in the museum, leaving most of the exhibits without the ability to come to life at night. After the exhibits are moved, Larry receives a phone call from Jedediah, who informs him that Dexter the monkey stole the tablet and took it to the Smithsonian, bringing every exhibit in it to life. Larry travels to Washington, DC, navigating his way to the archives with help from his son Nick while posing as a night guard.