"Homer Alone" is the fifteenth episode of Season 3. This is also the 50th episode of the overall show.
When the family causes Marge to flip out, she takes a vacation at Rancho Relaxo, leaving Lisa and Bart with Patty and Selma, and Homer alone with Maggie. Then, Maggie goes searching for Marge while Homer struggles with the former duties of Marge.
Marge has been under a lot of stress at home since the family takes her for granted, and she lashes out by blocking traffic at the Springfield Memorial Bridge, and causing all of Springfield to see when it is placed on the news (although there is plenty of bumbling as Kent Brockman is bonked around and Arnie Pye drops his bagel). When Chief Wiggum calls Homer in to talk to Marge, he manages to clam her down enough to tell her that he's sorry for taking advantage of her and that he loves her. She is moved by this and exits the car, but is later arrested by the police. Mayor Quimby and Wiggum are locked in a stand off. Wanting to have the female voters on his side for a political gain, Quimby orders him to release Marge. Wiggum refuses by pointing out how much she's angered the motorists in Springfield with her forced gridlock and refusing to move her car. He makes his case clear that Marge is a danger to the town and must remain locked up. Quimby refuses to budge on the issue and telling Wiggum off that if they keep her in jail, the women will protest against them. Marge is released from jail.
Later on, Marge notices a TV commercial for a resort spa called "Rancho Relaxo", and plans that she needs a vacation. Homer tries to talk Marge out of it by reminding her of failed family vacations from the children's misbehavior and how they ended up staying home because of it. Homer also mentions of not being pleasant company when he and Marge goes on vacation together. Marge convinces Homer that she needs to go to Rancho Relaxo alone for rest and relaxation.
Before leaving town, Marge puts Bart and Lisa into the care of Patty and Selma, but Maggie clings to the front door when she is about to be deposited to her aunts, leaving Maggie in Homer's care.
While Marge is enjoying her vacation, the rest of the Simpsons are suffering without her. Bart and Lisa are having pain in the care of Patty and Selma. Bart has to sleep with Patty, who snores, as Lisa has to sleep with Selma. Homer finds it troublesome feeding Maggie, and changes Maggie's diaper by closing it with a staple gun. As for entertainment, Homer tries to make Maggie laugh through a puppet show, only to scare Maggie. Santa's Little Helper attacks both the puppets and Homer, to which Maggie applauds and laughs.
Homer later invites Barney over to help him, but realizes how much he needs Marge to take care of things, especially when the following morning Homer finds Maggie has gone missing. Maggie left the Simpson house by herself as she was distressed at the absence of Marge. Homer and Barney then look for Maggie, but can't find her. Homer calls the Department of Missing Babies, goes to Marge's sisters to ask Bart and Lisa if they have seen Maggie. As they haven't, but try to make it clear they are desperate to get away, after being put into slavery having to rub the sister's feet. After a long search from Homer and Barney, Homer calls the police to help him. Marge, having thoroughly enjoyed her vacation, calls it quits, and calls Homer. Telling him she is feeling much better, Homer convinces her matters are under control at home. Marge reveals she is coming back and Homer should pick her up in one hour at the train station.
Maggie is then found on the edge of the top of an ice-cream shop by the police. Chief Wiggum thinks she is trying to commit suicide, but she is actually sleeping next to the statue of an ice-cream cone that looks like Marge's head. Not knowing the police have found Maggie, Homer prepares to apologize to Marge. He first talks to himself, but then Chief Wiggum arrives and returns Maggie to Homer. Homer then duct-tapes Maggie to her car seat, securing her tightly to avoid her escaping from him. He then makes his way over to Patty and Selma, to pick up Bart and Lisa. Overjoyed with his presence, they cling onto his feet and forcing Homer kick them into the backseat.
On the train, Marge glances at a photo of her family, comparing it to the lesser-good looking family that greets her. In the evening, Marge says she appreciates Homer helping her around the house, to which Homer gladly agrees. Marge then continues asking her requests for help, upon which Bart convinces her that they will do all the chores to help her out. This shows the kids are sleeping with their parents. The family then calls it quits, and goes to bed.