"Marge vs. the Monorail" is the twelfth episode of the fourth season of the American animated television series The Simpsons. It originally aired on the Fox network in the United States on January 14, 1993. The plot revolves around Springfield's impulse purchase of a faulty monorail from a conman, and how it subsequently falls to Marge to stop the train from destroying the town. The episode was written by Conan O'Brien and directed by Rich Moore. Recurring guest star Phil Hartman provided the voice of Lyle Lanley, while Leonard Nimoy made a guest appearance as himself. "Marge vs. the Monorail" has been widely praised by fans and critics and is generally considered one of the best episodes of The Simpsons. O'Brien has said that, of the episodes he wrote, this was his favorite. Nimoy's unexpected guest appearance was also widely praised. Despite this, the episode attracted some criticism when it was first aired due to the somewhat abstract and less situational nature of the plot, particularly from voice actor Yeardley Smith who in 1995 described the episode as "truly one of our worst". Plot When the Environmental Protection Agency fines Mr. Burns $3 million for dumping nuclear waste in a Springfield park, a town meeting is held to decide how to spend the money. After a few suggestions—including one from a poorly-disguised Burns to invest it back into his power plant—Marge nearly convinces them to repair the rundown Main Street but a fast-talking salesman named Lyle Lanley leads a song-and-dance routine that convinces the townspeople to instead build a monorail. After running a questionable training program, Lanley randomly selects Homer as the monorail's conductor. Doubtful about Lanley, Marge visits his office and discovers he intends to run off with money skimmed from the project, leaving the townspeople with a defective train. Marge drives to the town of North Haverbrook, a previous purchaser of one of Lanley's monorails. She discovers the town and its monorail in ruins. She meets Sebastian Cobb, the engineer who designed it and he confirms that all of Lanley's monorail projects are scams. Cobb offers to help Marge prevent Springfield from suffering the same fate. At the Springfield monorail's inaugural run, Lanley arranges for Leonard Nimoy to be present at a well-attended opening ceremony, which is a diversion that enables him to escape on a plane to Tahiti. When the flight makes an unexpected stopover in North