Mclean and her dad are trying out Luna Blu, the latest restaurant that her dad has been sent to fix-up. They've just moved to Lakeview, their fourth move in two years ever since Mclean's parents divorced. Her mom is still living in her old hometown, Tyler, with her new husband—basketball coach Peter Hamilton—and her new twin babies.
When they get back to their new house, Mclean starts unpacking and getting everything set up. She's startled to find a boy napping on their back porch, but he sneaks back to the house next door. In the middle of the night, she hears music playing and goes out to the house on the other side—a college party house. She hangs out for a bit and meets some people who are in her high school too, including a girl named Riley who is best friends with Dave, the kid she ran into on her porch.
She almost starts a new Ume.com (think: Facebook) account with a new name—like she does in every town she moves to—but instead decides not to. In every other town, she's gone by a different name and persona.
In the meantime, things at the restaurant are going poorly. The manager, Opal, resents Mclean's dad coming in and changing everything. She's also currently trying to put together a model of the entire town for the centennial, and needs help—Dave volunteers because he needs to do community service hours after getting caught with a beer at a party.
Mclean goes to school and is accosted by a peppy girl named Deb who claims to be the school's hospitality committee. Riley and her friend Heather call Mclean over, and they eat lunch together—Mclean feels sorry for Deb, who is sitting all by herself. Later, Mclean gets a phone call from Opal telling her that her dad's been in an accident and needs his insurance card—she asks Deb for a ride to the hospital, and the two become friends.
Mclean begins to feel more comfortable in Lakeview. She still struggles with her relationship with her mom—who she doesn't want to see or talk to out of a sense of loyalty to her father—but she's starting to make friends, and even gets attached to Luna Blu and the staff there. Along with Dave, Deb, Riley, and their other friends, they work on the town model to try to get it complete in time.
In the meantime, her dad tries to figure out how to keep the restaurant running, while dodging date invitations from a councilwoman who happens to be Opal's all-time nemesis. Mclean also starts to develop romantic feelings for Dave, which are obviously reciprocated. Mclean's mom goes to the lawyers to try to revisit the custody agreement, so Mclean agrees to visit more and to come to her mom's new beach house for spring break.
Right before spring break, Mclean finds out that her father just got another job offer in Hawaii and that Luna Blu will be shutting down for good. While reeling from this information, she discovers—to her horror—that her friends have found her previous Ume.com accounts and that they know that she had all these different personas at her last schools. Ugh.
She goes to the beach house with her mom to escape talking to anyone. While there, she overhears her mom talking to a friend about how this is all a mistake and assumes that she's talking about having Mclean with her for a week. Feeling hurt and out of place, Mclean grabs her old car and runs to the Poseidon, the cheap motel where she and her mother used to stay on their trips. She calls Dave to tell him where she is and says that she wants to date him—he says that he'll be there soon.
Instead of Dave, though, Mclean's parents show up and realize how hard the divorce has been on her. Her dad takes her back to Lakeview, and she goes back to working on the town model with Deb, finding that her friends don't think that she's weird at all; they just want to be there to support her. Dave isn't working on the model town because he's been grounded after he tried to take his car out—Mclean realizes that he did try to come see her at the Poseidon but was caught by his parents. Aw…
Eventually they finish the model of the town, and when it's done, Mclean goes to look at it and sees that Dave has put little figurines of her everywhere where they shared a memory in the town. He also wrote the word stay on the roof of the abandoned house behind his. Cue romantic music: She finds him and they kiss for the first time.
Mclean discovers her dad and Opal together and finds out that they're now dating. They decide that after the restaurant closes, Mclean's dad is going to Hawaii for the job, and Opal will be buying out the building and opening her own restaurant. Instead of cutting and running like he usually does though, Mclean's dad plans to come back and help her with the new restaurant.
They also decide though, that Mclean will go back to live with her mom in Tyler for the remainder of the school year, which she isn't happy about. She resolves to stay in touch with her friends this time, and plans to try out a long distance relationship with Dave.
At the last minute though, her mom tells her that she can't uproot Mclean yet again. Three cheers for Mom, right? Opal offers Mclean her spare room, and Mclean decides to move in and spend the remainder of the school year in Lakeview. She gets to graduate with her friends, and ends up working in the restaurant that Opal opens. As the book ends, she is planning to go to college.