Bart sneaks into Lisa's room to steal her propaganda and he finds her diary. Just before Lisa comes into the room Bart escapes with the diary. Bart decides to make some changes to the diary and send it to "Springfield Publishing Contest", whos editor-in-chief is Seymour Skinner. After Skinner reads the diary he comes to Lisa and she finds out that Bart sent it in to the contest. Skinner wants to offer her a publishing contract.
The book becomes a success, but Lisa is worried that she did not have time to read the book before it went to the printers. Marge decides to read the book and is not happy about what Lisa wrote. Lisa explained that someone had modified the text and Bart acknowledges that he did it. Marge wants to stop the printing but when she gets the first check of $45,000 she quickly changes her mind. Lisa gets a new style and become popular, but after a while, Lisa is not on the best seller list and she returns to her normal self. The family sits down and watches TV where they discover that Bart was paid to get the viewers to believe that he knew the truth about one of Mayor Quimby's illicit relationships and revealed that he is only a ten year old boy pulling a prank. Quimby calls Bart and thank him for what he did. The next day Lisa inaugurates a bookstore where Troy McClure comes and says he wrote the book and Lisa plagiarized it.
There was a trial over who owns the rights to the book, in which Bart helps Lisa after she runs into legal difficulties. Three months later, there's a queue outside the book store and it turns out that Bart has written a book about how he won the case which makes Homer mad, prompting him to chase Bart.