While hosting a party in his Manhattan penthouse, financial publisher Chris Thorne (Chevy Chase) meets investment attorney Diane Lightson (Demi Moore), a distraught young woman whose fiancee recently broke up with her. Wanting to get to know her better (in order to hook up with her) Chris agrees to escort her to Atlantic City on the following day to a sales conference. Brash "Brazillionaire" brother and sister Fausto and Renalda Squiriniszu meet up with them and invite themselves along.Along the way, Chris takes a supposed scenic detour off of the New Jersey Turnpike, ultimately ending up in the run-down mining village of Valkenvania. Failing to comply with a stop sign and subsequently attempting to escape pursuing officer Sheriff Dennis Valkenheiser (John Candy), the group is captured and taken before 106-year-old Reeve (Judge) Alvin Valkenheiser (Dan Aykroyd), who confiscates their identification cards and drivers licenses.The judge holds the offenders in his courthouse/funhouse to be judged the next day. They attempt an escape, but due to a series of mishaps, the group splits up. Fausto and Renalda escape by swimming across a sewage-infested moat around Valkenheiser's "funhouse" only to be captured by Officer Dennis, where they cut a deal with him to let them escape. Dennis decides to quit his job as an officer. At ties, Chris and Diane, still trapped within the house, are at high risk of being shot by Dennis's trigger-happy cousin, Officer Miss Purdah.Judge Valkenheiser is angered by their actions and imprisons Chris and Diane in a room from which the pair eventually escapes (again with a little help from Dennis) and, in time, become separated. Diane makes it out of the house and into the property's salvage backyard; here, she meets two ugly troll-like creatures by the names of Bobo (also Dan Aykroyd) and Lil' Debbull, the judge's severely deformed grandchildren whom are not allowed in the house. Earning the creatures' trust, Diane catches glimpses of Alvin's mute granddaughter/personal mechanic Eldona (John Candy, in drag) destroying Chris' prized BMW 733i.Meanwhile, Chris sneaks into the judge's personal quarters but is quickly caught by Eldona. Judge Valkenheiser punishes him according to house policy, which decrees that Chris must marry Eldona in exchange for his life. Chris pleads for help from another set of Reeve's victims, the alternative rap group Digital Underground. Although the group's members are being held on charges of speeding, the judge releases them after being charmed by an impromptu performance of one of the group's hits.It is revealed here that the judge and his household have a long-standing grudge against "bankers" (in which category they seem to be able to place everybody with more money than themselves) because of the loss of most of the family's wealth due to a poor coal investment deal back in the late 1910s. The judge's invariable punishment for being a "banker," and for just about everything else, is to be fed via roller coaster into a death machine called "Mr. Bonestripper," and have one's remains (human bones) shot out onto a large charnel heap. The machine breaks down the instant before Chris is fed into it, and he escapes. After retrieving Diane from the scrapyard, the two jump on a passing train back to New York.After the two report their plight to the authorities, Judge Reeve's courthouse is raided by local and state police. Chris and Diane are asked to accompany the officers to the site, only to find out that ALL of the officers involved are fully aware of and in league with the devilish Reeve. The couple only escapes when the area's underground coal fires cause a collapse, destroying the town and killing practically the whole village including Miss Purdah, the two trolls, and Eldona.Meanwhile, Fausto and Renalda, are shown to have made their way back to South America in their home city of Sao Paolo, Brazil. Dennis is now their personal head of security and Renalda's lover.In the final scene, Chris and Diane are shown relaxing back in New York at Chris's apartment, happy that their nightmare is over, and of the two of them finding love with each other. When Diane goes to the bathroom to take a shower, Chris's relief does not last. When he turns on his TV set for the evening news, he stumbles on a televised news segment covering the ruined town of Valkenvania destroyed by the mine collapse, and he sees one of the surviving residents is Judge Valkenheiser, brandishing Chris's ID that he left behind, where he announces to the reporter that he and his family plan to move in with his new grandson-in-law in New York City! In a panic, Chris gets up and escapes, smashing through a wall in his apartment making a cartoon-line outline while screaming: "No, you're not!!!"THE END