When Homer forces the kids to take classes at the rec. center, Lisa befriends an intelligent and imaginative girl named Juliet , who is, like her, a fan of Josh Groban. The two create a fantasy world named "Equalia", and grow ever more subsumed in it, becoming distracted from reality. Juliet in particular seems to be using "Equalia" to escape from her troubled relationship with her father, who neglects her interests in favor of his academic specialty of John Grisham. After meeting Juliet's family, and learning of Lisa's increasingly distracted performance in school, Marge becomes concerned about Lisa's friendship with Juliet, and forbids Lisa from seeing her. In response, Lisa and Juliet run away to a derelict restaurant (designed like a castle) to live out their world of "Equalia". Unfortunately, Jimbo, Dolph, and Kearney are also using the restaurant as a hideout, and imprison the girls. Juliet and Lisa manage to escape by entrancing Kearney with their tales of "Equalia" (causing him to turn on Jimbo and Dolph when they try to burn the "Equalia" manuscript), but when Lisa tells Juliet that she has to live in the real world, Juliet abandons the friendship (causing Lisa to conclude that Juliet is crazy).
Two months later, Lisa receives a publisher's rejection letter after attempting to get her "Equalia" book published, but she inspires Homer to create his own fantasy world (which goes no further than him re-imagining the family in forms more pleasing to him—Bart is a hot dog, Lisa is a starfish, Marge is a bottle of Duff Beer, and Maggie is a monster truck).
The episode was written by Brian Kelley and directed by Matthew Nastuk. A special version of the end credits theme was performed by Fall Out Boy, who were named after a character in the series, but they did not guest star in the actual episode. Emily Blunt guest stars as Juliet. This is also the last episode to be animated in SD format.
TV Verdict wrote: "It’s no secret that The Simpsons isn’t what it used to be. The past few seasons have been hit or miss, but once in a while an episode comes along that reminds me why I’ve kept watching. 'Lisa the Drama Queen' is one those episodes."