Plot

Soon after her divorce, a fiction writer returns to her home in small-town Minnesota, looking to rekindle a romance with her ex-boyfriend who is now happily married and has a newborn daughter.

Thirty-seven-year-old Mavis Gary seems incapable of happiness. She has had one failed marriage with no romance on her immediate horizon. She ghost-writes a young-adult series of books, which has just been canceled due to low sales. She is in the process of writing the last book, with which she is having a mental block. She lives vicariously through Kendall Strickland, the teenage female heroine in her books, as like Kendall she believes her high school years were the best years of her life when she was the prom queen. When she receives news that her high school beau, Buddy Slade, and his wife, Beth Slade, have just had their first child, Mavis takes it as a sign that she and Buddy are meant to be together. As such, she devises a false pretense to travel from Minneapolis back to her old hometown of Mercury, Minnesota, to reclaim Buddy from Beth. As Mavis slyly or not so slyly does whatever she can to hang out with Buddy, even in Beth's company if need be, she also runs into another old high school colleague named Matt Freehauf. She barely remembers Matt until she is reminded that he was the "hate crime" kid, i.e., he was beaten almost to death by the school jocks who believed he was gay (which he is not), which has left him among other things needing to walk with a brace. Matt ends up being Mavis' drinking buddy and confidante; Matt, in turn, tries to be Mavis' voice of reason to get her out of her delusional state about Buddy and get a grip on reclaiming her life as a functioning adult.—Huggo

Mavis Gary, once the high school 'It Girl', now an alcoholic divorcée who writes a soon-to-be-canceled young-adult fiction series, makes the decision to return to her childhood home in Minnesota. There she embarks on a plan to win back her former sweetheart, Buddy. The fact that Buddy is now married with a baby doesn't dissuade her. Along the way, she forms a bond with Matt Freehauf, another former classmate, who has been left disabled by a beating he took from a bunch of jocks.—Anonymous

Mavis Gary (Charlize Theron) is a divorced, alcoholic 37-year-old ghost writer of a series of young adult (industry term for new teenagers) novels, who is on deadline with her editor to finish the last book of the soon-to-be-canceled series due to low sales. Mavis lives a very lonely life and has no friends or boyfriend to speak of. Mavis is cynical, self-absorbed and looks down upon everyone's achievements which is why nobody can even stand her. Jim (J. K. Simmons) is Mavis' boss who is pressing her to complete her last book.

Mavis is in the process of writing the last book, with which she is having a mental block. She lives vicariously through Kendall Strickland, the teen-aged female heroine in her books, as like Kendall she believes her high school years were the best years of her life when she was the prom queen.

Mavis receives an e-mail with a picture of the newborn daughter of her high school boyfriend Buddy Slade (Patrick Wilson) and his wife Beth (Elizabeth Reaser). Mavis thinks that the picture is a slap to her face. Believing this to be a sign she and Buddy are meant to be together, Mavis leaves Minneapolis and returns to her hometown of Mercury, Minnesota, to reclaim her life with Buddy, under the pretext of overseeing a real estate deal.

Mavis spends the entire drive listening to "The Concept" by Teenage Fanclub on repeat from an old mix-tape Buddy gave her in high school. Upon arriving, Mavis checks into the Hampton Inn motel and arranges to meet Buddy the next day at a local sports bar, for old times' sake. Buddy is a new dad and so cannot do spontaneous catch-ups and wants to meet at 6 pm instead of 8 pm.

In the interim, Mavis goes alone to a different bar, Woody's. There she reconnects with a former classmate she barely remembers, Matt Freehauf (Patton Oswalt), who became disabled after being beaten by jocks (with a crowbar) who erroneously assumed he was gay. Mavis remembers Matt as the "Hate Crime Guy". Matt clarifies that once people discovered that he was not gay, the crime was not tagged as a hate crime, but only a fat guy being beaten up by jocks.

After getting drunk, Mavis reveals to Matt that she has come to win Buddy back as she believes that they are meant to be together. Matt tells Mavis that her plan to destroy Buddy's marriage is irrational and selfish, but she ignores him. Mavis says that in real life people do get divorced, but it takes a bit longer and she is in town to accelerate the process. Mavis believes that her love will conquer every obstacle in her path.

Meanwhile, back at her hotel, Mavis continues to work on her book as she evolves Kendall's story through her own life experiences. Mavis prepares for her date by getting a pedicure, shaves her legs, and even gives herself a facial. The following day, Mavis meets Buddy at the sports bar, where they run into Matt, the bar's bookkeeper. Mavis had dressed very provocatively for the date but turns out the bar was also a family themed restaurant, and it was Mavis who was out of place.

Mavis tells Buddy that she is now divorced. On their way out, Buddy invites Mavis to a performance of Beth's "mom rock band".

Mavis later calls Matt and says that she had Buddy has years of history which is complicated. Mavis ends up spending another night getting drunk with Matt, who distills homemade bourbon in the garage of the house he shares with his sister Sandra (Collette Wolfe). Mavis says that Buddy is not happy in his marriage and that Buddy told her so himself.

Mavis goes to a local book store and finds her books on clearance which depresses her. When Mavis attends the concert of Beth's band, the other moms are resentful of Mavis, whom they remember as the "psychotic prom queen b***h". When Beth's band performs, the lead singer dedicates their opening song to Buddy from Beth and much to Mavis's dismay, it is "The Concept". Beth wants to stay out longer, so Mavis offers to drive the drunk Buddy home. On the lawn they share a kiss that is quickly broken up when the babysitter opens the front door to greet them.

The next day, after an awkward encounter with her parents, Mavis is invited to Buddy's daughter's naming ceremony. She later goes out drinking with Matt again, during which Matt tells Mavis to grow up. The following day, Mavis attends the party, where she declares her love for Buddy, but he rebuffs her. Everyone at the party is called out to the lawn to await a surprise Buddy has prepared for Beth. Mavis, who has been drinking at the party, collides with Beth, who accidentally spills punch on Mavis's dress. Mavis insults her, and in a profanity-laced tirade tearfully reveals she became pregnant with Buddy's baby years ago, but had a miscarriage after three months.

Buddy, who has been preparing a drum-set gift for Beth in the garage, opens the garage door and belatedly learns what has transpired. Mavis asks him why he invited her. He reveals it was Beth's idea, as she feels sorry for Mavis. Humiliated, Mavis leaves the party and visits Matt, where she breaks down in tears and, later, initiates sex.

The following morning, while Matt sleeps, Mavis has coffee in the kitchen with Sandra, who still idolizes her. Mavis talks about needing to change herself, but Sandra says Mavis is better than the rest of Mercury and should not change. Mavis says she agrees and prepares to return to Minneapolis. Sandra asks to go with her, but Mavis declines and leaves alone.

In a diner on her way home, Mavis writes the last chapter of the book, in which the main character graduates high school, quickly leaves her past behind and looks forward to the future. Afterward, in the parking lot, Mavis contemplates her damaged car, still crumpled from an earlier incident during which she was driving it drunk.