Tony Miglione, a nearly 13-year-old boy in Jersey City, New Jersey, narrates his family's sudden rise to wealth and the upheaval it brings. He delivers newspapers and plays basketball every weekend with his close friends: Frankie Bollino, Big Joe Rosella, Little Joe Schenk, and Billy Turner. His father Vic is an electrician, his mother Carmella works at a department store in Newark, and his older brother Ralph, a social studies teacher, lives upstairs with his wife Angie. Tony's maternal grandmother, who lost her larynx to cancer two years earlier, does all the cooking and communicates through gestures and notes in Italian. Tony's other brother, Vinnie, was killed in Vietnam; the family rarely mentions him because it makes Tony's mother cry.
One evening, Ralph announces that Angie is pregnant. The family reacts with gloom because they cannot afford a baby. Grandma writes a note insisting the baby be named Vinnie; Tony's mother tears up as she and Grandma touch hands. Tony's mother takes extra shifts, Ralph picks up a second job, and Vic retreats to his basement workshop. Then Vic starts leaving each morning in his best suit, carrying a small metal box and refusing to explain. Tony's worry spirals, triggering the stomach pains he has experienced since January. His parents reveal that Vic brought an electrical cartridge invention to J. W. Fullerbach, head of J. W. Fullerbach Electronics, who wants to manufacture it and hire Vic. The family is moving to Rosemont, a town on Long Island. Tony, devastated at leaving his friends, locks himself in the bathroom and cries.
Tony keeps the move secret through the school year. Only Frankie stays supportive; Tony gives Frankie his cherished school pennant, once Vinnie's, and Frankie gives Tony an English coin. On July 20th, the Migliones move into a large white house with five bathrooms and thick yellow carpeting. When Mrs. Hoober, the golf-playing neighbor, implies Vic's old work truck belongs to hired help, Vic sells it and buys a new Ford, a decision Tony suspects is about fitting in. For his 13th birthday, Tony receives the red 10-speed Schwinn he has always wanted.
Joel Hoober, the neighbors' son, introduces himself with polished manners that impress Tony's parents but strike Tony as phony. Joel invites Tony to swim in the heated pool. When Joel's 16-year-old sister Lisa emerges in a bikini and performs a swan dive, Tony is immediately captivated. He spends the rest of summer at the Hoobers' pool, watching Lisa. When junior high begins, Tony befriends classmates Marty Endo and Scott Gold and joins the Junior Youth Group at church, led by Ted Gibbons, a college sophomore. A girl named Corky develops a crush on Tony, which he finds annoying.
Tony grows anxious about puberty, worrying about involuntary erections and feeling he has no control over his body. One afternoon, Joel casually pockets three flashlight batteries from a store without paying. Tony is torn but says nothing; his stomach pain flares. That night at the Hoobers', Joel leads Tony into Lisa's off-limits bedroom to find her diary, but they discover only a mocking note. Tony notices that Lisa's bedroom window faces his own room.
Angie gives birth to a girl named Vincenza, called Vicki, after Vinnie. Tony's mother hires a forceful maid named Maxine who demands control of the kitchen, displacing Grandma from her beloved role as cook. Grandma retreats to her room in protest, and Tony resents his mother's capitulation. One evening, Tony realizes that with his lights off and Lisa's on, he can see into her bedroom. He begins watching her undress and becomes fixated. He has his first wet dream, featuring Lisa and Corky, and wakes confused before recognizing what happened. He adds binoculars to his Christmas list, claiming he wants to watch birds.
On Christmas, Tony uses the binoculars to watch Lisa try on a sweater, convinced he is falling in love. Mrs. Hoober gives Tony's mother a new name, "Carol," because Carmella is supposedly too hard to remember. Tony erupts, comparing this to how the Hoobers replaced their maid's Spanish name, but his father explains that a name does not change who a person is. On Veterans Day, the family visits Vinnie's grave. Tony watches his mother cry and Grandma kiss the headstone, feeling like an outsider in his family's grief.
Joel pressures Tony into making prank phone calls. When the targeted woman threatens to call the police and Joel insists Tony call again, Tony refuses, doubled over with pain. Dr. Frank Holland diagnoses Tony with "nervous stomach," functional pain caused by internalized tension, and advises him to express his feelings. In a Youth Group basketball game, Tony makes a crucial foul shot to help win but discovers during the celebration that Lisa is dating Ted. His old friend Frankie visits for a night that ends with Tony, Frankie, and Joel getting drunk on liquor from the Hoobers' bar.
Tony learns that Ralph plans to quit teaching and join J. W. Fullerbach's company. He views Ralph as a sellout and avoids him. When his anger surfaces, he collapses with severe pains, retreats to Grandma's room, and cries in her lap, recognizing they are both outsiders in their own home. When Joel pockets two pens from a corner store, Tony collapses on the sidewalk and is admitted to North Shore Hospital for 10 days. Tests confirm his pains are functional, and he is referred to Dr. Fogel, a psychiatrist, for ongoing therapy.
At his first session, Tony surprises himself by talking freely about Joel's stealing, his mother's treatment of Grandma, Ralph abandoning teaching, and his father's obliviousness. Dr. Fogel listens and asks open-ended questions. Back at school, Tony's pains lessen. He tells Dr. Fogel about watching Lisa; the therapist asks how it makes him feel but does not tell him to stop. Ralph and Angie announce they are buying a house near the Migliones. Tony reflects that children do not always want their parents to give them everything, and he processes his feelings without getting pains, a sign of growth.
At the Village Sports Store, Joel slips golf balls into his bag, unaware the store has installed closed-circuit television. Employees confront Joel outside, and Joel screams at Tony to vouch for him. Tony remains silent, realizing he can manage without Joel. Joel admits he stole for the thrill and describes his father as someone who deals with problems by putting them away, calling himself "problem number one." Joel's father sends him to a military academy in the fall. When Mrs. Hoober tells Tony's mother that Joel is attending for the superior discipline, Tony's mother suggests Tony go as well, but Tony chooses to stay.
The story closes on June 10th. Tony rides his bike through Rosemont, thinking about turning 14 and the swimming pool his family is building. He coasts down a hill with his feet over the handlebars and laughs aloud. He dreamed the previous night not about Lisa but about Corky, who looked like Lisa in the dream. Tony decides he will put his binoculars away on the top shelf of his closet, where they are hard to reach. "Then again, maybe I won't" (169), he thinks, leaving his struggle between impulse and self-awareness unresolved.