Marge starts up a new women-only gym in Springfield and Homer frets about losing her after she becomes a highly successful businesswoman. Meanwhile, Coolsville, a new comic book shop, opens up in Springfield and puts Comic Book Guy out of business.
While shopping at the The Android's Dungeon, Milhouse accidentally sheds a tear on a Wolverine comic book and blurs Wolverine's sideburns. For this, Comic Book Guy charges Milhouse twenty-five dollars to buy it. After Bart complains that if Comic Book Guy should treat them right since they're his customers, Comic Book Guy tells him and the other child customers to go to a new comic book store, thinking his is the only game in town. To his surprise, a new comic book store, "Coolsville Comics & Toys", situated directly across the street from the Android's Dungeon has just opened.
All the children immediately depart the store and head towards Coolsville, where the store owner, a hip man named Milo immediately makes a good impression on the kids by giving them candy and inviting them for his grand opening. Upon entering, the children are astonished to see the store is not completely full of comic books, but also of video games and modern art, giving it a sophisticated arcade look. When Lisa accidentally rips a page of a book, Milo merely tells her that the books are meant to be read and enjoyed, not hoarded.
The store begins attracting popularity, including that of alternative comic creators Art Spiegelman, Dan Clowesand Alan Moore, who all visit for a book signing. Comic Book Guy's jealousy begins getting to him, so he begins to sabotage Milo's popularity by attempting to bribe the children with new ninja weapons, and outing that (unlike normal comic collectors) Milo has a girlfriend named Strawberry, who appears to be as cool as he is. After these ploys do not work, Comic Book Guy takes out a sword and demolishes Coolsville. He fails to destroy more after Art Spiegelman, Dan Clowes and Alan Moore subdue him.
After dropping Bart off at Coolsville, Marge compares herself to a cardboard standup of Wonder Woman, and is shocked to see how her physique compares unfavorably. Then Jimbo, Dolph, and Kearney start feeling sorry for Marge and start beating up each other because of their mothers' appearances. Marge promises to go to a gym and become slimmer. While exercising at a large and intense gym, Marge begins to struggle with the treadmill. She convinces herself that everyone else is struggling, but feels worse when she realizes that she's the only one as the other clients, including Miss Springfield, Cookie Kwan, Rainier Wolfcastle, and Duffman who all have above average physiques are all using the treadmill with no problems. After being embarrassed from showering in a public shower, Marge wishes to make a gym for ordinary women were they won't be embarrassed in front of people.
When Comic Book Guy finally gives up, he sells the Android's Dungeon to Marge who creates Shapes, a women-only workout center which immediately becomes a hit. Many women of Springfield comment on Marge's efforts, and she opens another location at an abandoned Krusty Burger. Soon, after an interview on Opal, a now rich Marge becomes an international hit.
Homer and Marge go on a luxury vacation at a hotel where Homer meets a group of three jocks. They begin to convince Homer that Marge will soon dump him for a healthier man. The men give Homer a list of the stages Marge will go through before dumping him, which all start to happen. Later, Homer overhears Marge talking to a group of women about dumping something. Homer assumes it is him, although it is really Marge's purse.
As Homer is worrying about what to do one of the husbands reveals that he's actually a first husband, he gives Homer advice on how to be more attractive to his wife. Including exercise, keeping with trends and a proper diet. Naturally Homer ignores all this as they require effort on his part in favor of stomach staples and plastic surgery. When finished, Homer looks entirely different from his first appearance. However he has a massive amount of loose skin that he's embarrassed to show Marge. He goes back to the doctors and demands that he get every single procedure the surgeon can perform. In the result, Homer's appetite level has been significantly lower and tear ducts have been moved to his pectoral muscles. While Mayor Quimby begins rewarding Marge for her work with Shapes, Homer arrives in his new form, much to the shock and disgust of the town. Quimby soon orders the town to raise their pitchforks and attack Homer. Homer and Marge run to the top of Springfield's Notre Dame tower and Marge, saying she wants a trophy husband, deliberately pushes Homer off the tower. Homer wakes up in the hospital, back to his old self. Marge informs him that after he was knocked out, the surgeon called for her permission on the surgery, to which she said no, and that everything from Homer's blacking-out to his "death" was just a dream. She did have the doctor reverse Homer's stomach stapling, as she loves him no matter how he looks. The episode ends with Moore, Spiegelman, and Clowes watching Homer and Marge leave, and they mention that a meteor is headed for Earth, but soon forget at the mention of a convention for underpaid writers, to which to fly away to as the meteor is about to strike.
It is unknown what happened to the Shapes business as it is never mentioned again. Marge may just be earning money while someone else works for her.
Robert Canning of IGN enjoys this episode most out of the season so far, and calls it an episode that can keep viewers entertained and laughing. He called the character of Milo and Jack Black a perfect good fit, particularly enjoying a Korean version of Tom Jones' "What's New Pussycat". Despite calling Jack Black's appearance great, he particularly enjoyed the appearances of comic book legends Alan Moore, Art Spiegelman, and Dan Clowes who happily parodied themselves; he quotes that the most enjoyable bits with them was seeing the dark, demented Moore find giddy solace in a Little Lulu book, when the three formed the "League of Extraordinary Freelancers" and seeing Spiegelman don a Maus mask, to make it all inevitable and hilarious. The episode had 10.55 million viewers, second best for the season.