Principal Skinner, anxious to maintain his Spring Break vacation schedule, closes school a day early and, in an inspired moment, invents Go To Work With Your Parents Day to keep students occupied. Bart spends his time alongside Patty and Selma at the Department of Motor Vehicles. When the sisters Bouvier are distracted, Bart gains access to the driver’s-license-making-machine, and manufactures his own fake I.D. Shortly thereafter, he rents a car. Meanwhile, Lisa accompanies Homer to the power plant and spends the day at his work station. Incredibly bored, Lisa suggests they try making the job a little more fun. Soon afterward, she and Homer don radiation suits and amuse themselves by pretending to be astronauts.

Bart, Milhouse, Martin and Nelson sneak off for a trip in the rental car by telling their parents that they are attending a National Grammar Rodeo. Scanning an old AAA guidebook, the boys choose the World’s Fair in Knoxville, Tennessee as their Spring Break destination. But when they arrive in Knoxville, they encounter the dilapidated remains of the old park. Shortly thereafter, a giant geosphere tumbles and destroys the rental car. Meanwhile, Homer realizes how much he enjoyed Lisa’s company at the power plant. He invites her to spend more time with him, and she eagerly accepts. During a night shift, they stage a slumber party and pass the time playing Truth or Dare. Lisa tells Homer it’s the best Spring Break of her life.

Stranded in downtown Knoxville without transportation or money, Bart places a collect call to his sister for advice. Lisa suggests that a courier service might have a flight to Springfield. Instead, Bart ends up on a flight to Hong Kong. Lisa decides to test her new relationship with her father. After making Homer promise not to get angry, and not to tell Bart about their discussion, Lisa reveals the truth about her brother’s whereabouts. Homer keeps his promise. He orders equipment for the plant and has it shipped via courier from Knoxville to the power plant. Bart and his friends stow away inside the huge shipping crate—unaware that Homer had arranged their trip home.