The novel jumps between Noah’s perspective of events in the past and the perspective of his twin sister, Jude, in the present. Noah’s story begins when they are 13. Introverted, artistic and beginning to experience homosexual feelings, Noah lives in the shadow of his fearless, extroverted and headstrong twin sister. Older boys in his neighborhood bullied Noah because of his odd personality and the fact that he always carries a sketchpad.
When their mother announces that the ghost of their grandmother told her the twins should go to a local art school, Noah has hope that his life will change for the better. He is ecstatic at the prospect of being with other kids like himself and works hard to create a portfolio of work so that he will be accepted. Although also artistic, Jude has no desire to go the art school. She longs for regular high school and the social life it entails. Their mother’s enthusiasm for Noah’s art makes Jude feel unloved.
Three years later, Jude takes over the story. Their mother was killed in a car accident, and Jude is now a student in the art school, but Noah was not accepted. All of Jude’s clay sculptures keep mysteriously breaking. Jude is convinced that her mother’s ghost is ruining her art. Her adviser does not believe the story but suggests she needs to work on a special project. He wants her to tap into the same creativity that made the sculptures that got her into the school.
Jude is stunned. She never showed the sculptures to anyone and has no idea who may have sent the school the photos of her sculptures. Although she has felt her mother’s spirit trying to force her out of the program, Jude begs to be given the opportunity to try sculpting something in stone. She has a piece she wants to create and knows her mother will not be able to break rock as easily as clay. Her adviser offers to contact a former teacher to see if he will tutor her, but the odds are slim. Always eccentric, the artist has refused to work with anyone in several years.
As the winter break is upon them, Jude decides she cannot wait for class to resume before she meets with the artist. His name is Guillermo Garcia and he lives nearby. Jude walks in the rain to his neighborhood. She takes refuge in an old church to dry off. Inside is a young man taking photographs. Jude has sworn off dating, but the photographer’s British accent, sarcasm and roguish good looks are hard for her to resist. She is relieved when he leaves.
Jude finally gets the courage to knock on Garcia’s door but he, in a drunken rage, promptly dismisses her. The young photographer answers her second knock and tells her it is not a good time, before shutting the door. Before she can knock again, she receives a text from her friend that Noah is going to jump of Devil’s Drop.
The story skips back to Noah’s point of view, now at 13 years old. He has been sneaking over to the art school to watch the classes through the windows. He becomes enamored with the young British man who serves as a nude model one afternoon. When the model takes a break to smoke a cigarette and drink from a bottle he’s hidden outside, he discovers Noah.
The two strike up a conversation, and the model admires Noah’s work. The model is eventually thrown out of the class for being drunk. Later, Noah sketches an abstract portrait of the young man. When Jude sees it, she insists he give it to her. Recalling a childhood game, she promises to give him the sun, moon and stars to gain the portrait.
Noah becomes friends with Brian, a 14 year-old visiting for the summer. Brian loves to talk about space and meteors, and soon Noah has a crush on him. He is too frightened of scaring Brian away, so he does not tell him of his feelings. When two neighborhood boys try to bully them in the woods, Brian uses the rocks he has been collecting as projectiles. He fires them at the boys with precision, accuracy and speed, until they run away.
It soon becomes known that Brian is a gifted baseball player, already being scouted by several college teams. When Brian takes Noah on the roof of his house to look through his telescope, Noah senses a romantic electricity between them, but again, does not act on the feeling.
Noah gets upset when Brian seems to be interested in Jude and some of her flighty friends. In a roundabout way, Brian explains that sometimes people act a certain way so they will not be alone, but it is not who they are inside. Jude becomes jealous when her friends start to hang around Noah and Brian. She feels as though Noah is taking everything from her. Noah and Jude attend the same party and get caught up in a game where a girl draws a boy’s name from a hat and then takes him into the closet to kiss for five minutes. Noah goes into the closet with one of Jude’s friends. He pretends she is Brian and kisses her passionately. Jude pulls Brian’s name from the hat. Noah is furious and runs away from the party. A chasm opens between him and Jude — one he has no desire to mend.
On his way home, he runs into the British art model. The young man talks about an artist, Guillermo Garcia, who teaches in his home nearby. The Brit says that Noah could sneak into one of his classes, and the artist wouldn’t even notice.
In the present, Jude returns to Garcia’s house, and with an almost insane confession of her need to sculpt, convinces him to take her on as a student. She is convinced that it is because he is as crazy as she is. She discovers that Oscar, the British photographer, lives with Garcia. The artist took the young man in several years ago after Oscar had almost killed himself with drugs and alcohol. Since that time, Oscar has tried to rehabilitate himself.
Although Jude fights the attraction, she finds herself inescapably drawn to him. Garcia begins her instruction, and she discovers a freedom in creating art that she has not felt in years. One afternoon Jude snoops through Garcia’s office and finds a passionate note he wrote to someone he loved. Jude knows that his gruff exterior is because he, too, lost someone dear.
Garcia warns her not to become involved with Oscar, but Jude cannot help falling in love with him. One afternoon, she and Oscar share stories about themselves that no one else has heard. The next day, Jude is crushed when she spies Oscar bringing home another girl. She runs from Garcia’s house, heartbroken.
Noah convinces himself that Jude and Brian are continuing their affair, even after Brian returns to boarding school. Noah sneaks over to Garcia’s house to watch him teach a class. The man’s talent and passion humble Noah.
Feeling inadequate in every area of his life, Noah flees the house. He stumbles across his mother, sitting in her car in Garcia’s driveway. Her behavior is bizarre as she makes excuses as to why she is there. Over the next few months, she begins to drift emotionally away from the family. Eventually, their father moves out of the house in a trial separation.
Christmas arrives, and Brian returns for a visit. When he and Noah go for a walk, Brian kisses him. Back in Noah’s room, the two are separately masturbating when Noah’s mother walks in. She immediately leaves the room, but Brian is panicked. He has already suffered hazing when kids in his first high school thought he was gay. He runs away and refuses to acknowledge Noah, even going so far as to date a girl. When Noah sees them together, he shouts the truth that Brian is gay and then runs away.
Noah’s mother tries to be understanding and promises not to tell his father, but Noah overhears her talking on the phone about needing to discuss him. When she leaves the house, he follows. He sees her meeting another man, Garcia. Later, Noah confronts her with the truth of her infidelity. She confesses and tells him she is going to ask his father for a divorce so she can be true to herself and be with the man she desperately loves.
In the present, Jude relives the past as she pounds her chisel into stone to release a sculpture of her and Noah. She admits how she was not there the day her mother died because she had been seduced on the beach by an older boy. Jude resented Noah’s grief and relationship with their mother so much that she only mailed her own application to the art school. She did not mail his.
As she rails against the stone, she frees herself from guilt. She will give her spot at the school to Noah. She will not depend on others to validate her worth. When she returns home, she receives a text that Noah is going to jump from an impossibly high cliff into the ocean. Jude runs to his rescue. She makes her way through the drunken crowd to find her brother. Before she can stop him, Noah runs toward the cliff.
Out of nowhere, Oscar tackles Noah, saving him from certain death. Oscar had been in the woods, contemplating drinking again, after almost a year of sobriety, when he saw Jude. He followed her and had the forethought to stop Noah. Noah finally admits the truth about their mother’s affair. Jude admits to sabotaging his chances at art school, and they forgive each other.
Noah admits his homosexuality to his father and reunites with his first love, Brian. Jude realizes Oscar is the boy in Noah’s portrait and enters a romantic relationship with him. With the weight of their lies gone, the family moves to a new home to begin a new stage of life together.