On a school field trip to the Springfield Aquarium, Bart climbs into a tank and moons everybody underwater. As he tries to get out of the water, he is grabbed by an octopus, punched in the stomach by a turtle and hit on the head by a hammerhead shark. As Bart's wounds are being treated at hospital, Marge realizes that Homer has their insurance card, and unsuccessfully calls around looking for him. He finally shows up at the hospital, explaining he got sidetracked by the TV previews at the video store. Marge insists that he get a cell phone, so that they can contact him whenever they need him. Lindsey Naegle walks into the hospital room hawking cell phones, and sells Homer one with a Mexican Hat dance ringtone.
The next day, Homer, taking advice from Barney, goes to buy a hands-free headset, and is tricked by the clerk into buying additional accessories that can be plugged into the car's cigarette lighter socket, including a DVD player, a snowcone maker, fog machine, record player, deep-fryer, and a Lite-Brite with Homer's face on it. Homer drives around using his new toys without paying attention to the road, until he realises he is on a pier headed straight for the ocean.
After his car is pulled out by the "Navy rejects", (the Coast Guard), Judge Constance Harm cancels Homer's driving license. Homer can no longer drive anywhere, which means that Marge has to do all the driving. While walking to Moe's Tavern Homer envies the people driving past. However, when he reaches Moe's he realizes that he feels great at having walked all the way and decides to keep going.
As Homer begins to enjoy walking, Marge begins finding her duty of driving everyone places increasingly stressful. One day as Homer walks with other Springfieldians, Marge accidentally runs him over with her car.
Later, as Homer recuperates from the accident, Hibbert tells Marge that Homer's crushed pelvis means that he is now utterly dependent on her. Marge accepts this and feeds Homer some soup, but it is too hot. She then (apparently accidentally) spills the soup in Homer's lap.
Later, Homer hobbles out with a cane, claiming he feels fine, much to Marge's annoyance, since she has to drive. She "accidentally on purpose" kicks out his cane, making him fall. When Homer tells her he thinks she's trying to hurt him, Marge tries to deny it, she accidentally blurts out that she hates him. They go to see a marriage counselor, and discover that Marge has subconsciously begun to resent Homer for his constant selfishness, exemplified when the two are asked to write a list of the three most important people in their life, and Homer just writes down himself with different names, and Marge leaves the room sadly. The counselor advises Homer to perform one completely unselfish gesture to win Marge back. He suggests a romantic dinner. So Homer decides to do one better and invites all the people of Springfield for a backyard barbecue in Marge's honor.
Marge, returning in a foul mood after driving, walks to the backyard and is welcomed by everyone. Jackson Browne sings a duet with Homer (to the tune of his song Rosie), praising Marge. After the barbecue, Marge tells Homer that she loves him. Homer and the other guests toast her, before Homer turns on the sprinklers once dinner is over to get everyone to clear out.