This story is told through a series of letters written by a freshman named Laurel. The letters are written to Kurt Cobain, Judy Garland, Amelia Earhart and others. Her letter writing begins as an assignment in her English class, but Laurel never turns in her letter to Kurt Cobain, the lead singer of Nirvana, who committed suicide. Instead, she continues to write to different dead people she admires.
Laurel’s sister, May, died the previous spring. Her parents are divorced, and her mother left for California after May’s death. Laurel lives two weeks of the month with her father and two weeks with her Aunt Amy. This allows her to switch districts and start her freshman year at a school where no one knows anything about her sister.
Laurel admits to Cobain that she does not know who she is. She hides in the bathroom to eat her lunch and then sits outside along the fence. It is there she first sees Sky, an attractive and mysterious boy who always wears a leather jacket, even in the summer.
Laurel continues to write to Cobain because it makes her feel closer to May, who introduced her to his music. Laurel describes the grief her family experienced after May’s death and her frustration at not being able to find a place to fit in. Laurel writes to Earhart in her third week at school, telling how she admired Earhart’s courage. She tells how that day she wore one of May’s outfits to school, faced her fear, and at lunch, walked up to Natalie, a girl from her English class.
Natalie introduces her to Hannah, and soon the three girls are sitting at the table and talking like they have been friends forever. They ask her to go to the state fair with them after school, and Laurel has a wonderful time. In a letter the following week, she tells Cobain that she shared her crush on Sky with her new friends. She finally feels like she fits in.
In her letters, Laurel describes her growing friendship with Hannah and Natalie. Hannah dates older boys, one of them is in college. This makes Laurel nervous. May dated a man named Paul, but she's not sure how they connect. Laurel gets drunk for the first time at a sleepover at Natalie’s house. She walks off, remembering how her sister would come home drunk from parties and wake her up to tell about her night. When Laurel returns to Natalie’s house, she sees her friends kissing. She promises not to tell anyone about it.
Laurel’s letters to Garland express her longing for her once happy family, just as Garland seemed to be searching for the innocence of her childhood. After May’s death, Laurel’s mother moved to a ranch in California. Now, Laurel feels abandoned and does not know what to say to her mother when she calls on the phone. Laurel writes to Allan Lane, one of her Aunt Amy’s favorite actors, about her life in her aunt’s house. Amy is forty 40, a spinster and a devout Christian.
In a letter to Amy Winehouse, Laurel tells how Hannah introduced her to two seniors, Tristan and Kristen. They are an artsy couple who take Laurel and her friends under their wings. They hang out in the alley of the school, smoke clove cigarettes and teach the girls about cool music, such as Janis Joplin and Guns N’ Roses.
Kristen tells Laurel a rumor that Sky got kicked out of his old school but no one knows why. A few days later, in a letter to Jim Morrison, Laurel writes how Sky met her in the hall at school and asked if she wanted to go for a ride. At first, she enjoys herself, but when Sky begins to touch her thigh, Laurel retreats to a memory with May. She does not explain what happened, only that she is scared. Sky senses her fear and holds her hand instead.
Their relationship begins to grow. As they become more physical, Laurel hints again at something having happened when she was with May, but she pushes the memory away and continues to make out with Sky. The flashbacks take a toll however, when she refuses to tell Sky what is wrong, even though he can sense she is keeping something from him.
Things come to a head on New Year’s Eve, after Laurel has had several alcoholic drinks. She longs to tell Sky the truth about what happened to her, but she is afraid. Instead, she tells him she is a fairy and tries to jump from a balcony. Sky stops her, but then leaves her with their friends. He does not return her calls over the winter break and officially breaks up with her when they return to class. He says that she has something broken inside of her, and he is powerless to help her.
Laurel writes about the relationship between Hannah and Natalie. Natalie admits she is in love with Hannah, and it is obvious Hannah loves her, but she is not ready to admit she is a lesbian. Instead, she gets into physical relationships with college-aged men.
One night, several months after Laurel’s breakup with Sky, the three friends attend a college party with Hannah’s boyfriend. Hannah’s older brother, Jason, is there and starts to cause a scene. He is angry that Hannah kept her boyfriend a secret from him.
A fight is avoided, but Laurel can sense the tension between Hannah, her boyfriend and Natalie. Laurel finds a corner by herself, but then joins several boys outside, one of whom, Evan, she knows from school. He offers her a beer and a “caffeine” pill. At first she refuses, but when she overhears one of the boys compare her to May, she takes it. Immediately, she begins to feel nauseated and dizzy.
Evan leads her back into the house. Thinking she is going to be sick, Laurel opens the bathroom door, only to find Natalie and Hannah passionately kissing. She closes the door, but not before others at the party have seen them together. Evan leads her to a bedroom. Although she asks him to stop, he proceeds to molest her. Laurel manages to stop him before he rapes her.
Sky comes into the room to make out with his new girlfriend, but then sees what is happening and threatens Evan. He takes Laurel home. On the way, he admits he knew May well and once had a crush on her. Laurel is devastated, even though he insists he only ever loved her. The next day, Laurel goes to Hannah’s house. Both she and Natalie are furious with Laurel. Laurel does not tell them how Evan tried to rape her so Natalie believes Laurel ditched them for Sky.
Laurel’s memories come hard and fast, and she writes about how, when May was 16, she asked permission to take Laurel to the movies with her to see Aladdin. At the theater, May leaves with her boyfriend, Paul. Thirteen-year-old Laurel is left behind with Paul's friend Billy. Instead of taking her inside to the theater, Billy takes her for a ride in his car and fondles her.
Laurel did not tell May what happened. May continues to use Laurel to hide her relationship with Paul. Once a week, for several months, May leaves Laurel at the theater with Billy while she parties with Paul. Billy continues to touch Laurel, and it is intimated that he forces her to watch him masturbate.
Laurel tells May what is happening the night Billy forces her to touch him. May, distraught, walks along the edge of a bridge, pretending to be a fairy, like she had when they were younger. Laurel does not believe her sister jumped, but fell, into the river. Laurel feels responsible for her sister’s death. She calls Sky and has him take her to the bridge. She tells him everything that has happened, thinking that he will no longer like her. Instead, he comforts and supports her.
Laurel now feels strong enough to approach Hannah before school. The two ditch class, and Laurel tells her everything that happened at the party and with May. Hannah shows her the bruises Jason gave her after the party. His anger is explosive, and he has hit her before.
Hannah and Jason live with their elderly grandparents, who do not see what is going on between the siblings. Hannah ends up moving in with Natalie and her mother, until Jason leaves for the Marines. Over the coming weeks, Hannah allows Natalie to kiss her at school.
As the school year ends, Laurel’s mother returns from California for a visit. Laurel finally opens up about Billy’s molestation and the night May died. In an epilogue, Laurel writes a letter to May and tells her that she and Sky are back together. She is seeing a therapist to help her work through all that has happened to her, and at the end of the school year, she gives her English teacher all the letters to the dead that she has written, except the one to May.
Laurel and her parents take May’s ashes to the bridge and empty them into the river. Laurel hopes her sister will get to see the ocean, as they had always dreamed. She knows, when she finally goes to the ocean herself, she will sense May’s presence in the waves.