A boy in high school has just moved and tries to make friends, but a daring game has tragic consequences. The three teens in this story have parents who do not understand them, and they try to cope on their own and with each other.
At night Jim Stark (James Dean) lays down on the street next to a doll. He is arrested and taken to the police station for drunkenness. Judy (Natalie Wood) cries and tells the detective Ray Fremick (Edward Platt) that her father hates her. He asks if she is seeking attention, but she says she will never be close to anyone. He asks her if she would like to go home or stay there. She gives him her phone number so that her father can pick her up.
Jim makes a siren sound and is warned to cut it out. He offers his jacket to John “Plato” Crawford (Sal Mineo). Fremick tells Judy that her mother will pick her up. Jim’s parents Carol Stark (Ann Doran) and Frank Stark (Jim Backus) arrive for him. Another detective asks Plato why he shot the puppies. His family’s maid (Marietta Canty) helps give information about his family. Jim has nothing to say. His father says they just moved there, and he has no friends yet. His parents argue, and Jim cries out, “You’re tearing me apart!” Fremick takes Jim into his office and suggests he take out his aggression against his desk. Jim hits it and kicks it, hurting himself. Jim says a kid called him chicken. Jim says he loves his father, and he wishes he had the guts to stand up to his mother and grandmother (Virginia Brissac). He asks how a guy can grow up in a circus like that. He wishes he could have one day without confusion where he felt he belonged. Fremick asks Jim to come in to talk with him if he feels he is in a jam. He asks if he is calm enough now, and Jim laughs. The grandmother says there will be no more trouble, and Jim implies she is lying.
At home Jim declines breakfast, and he sees Judy outside. Jim takes a bag lunch and leaves for his first day of school. His father advises him to choose his own pals. Jim says hi to Judy and walks with her as they talk. She asks if he wants to carry her books. He says he has a car and offers her a ride. She says she goes with the kids. A car full of boys comes up, and she gets in. One boy kisses her. Jim drives up and asks directions but gets little help.
At Dawson High School a little cannon goes off, and the American flag is raised. An older student tells Jim not to step on the school insignia. Jim says he is sorry. Plato opens his locker and combs his hair by a mirror.
A black car goes to the planetarium. Jim arrives late during the lecture and finds a seat. Dr. Minton (Ian Wolfe) talks about constellations. Some kids make jokes. Plato warns Jim not to monkey with a “wheel.” Dr. Minton talks about “being destroyed as we began.” He says the problems of man are trivial and of little consequence. After the lecture a teacher fails to get the students attention. Jim tells Plato it is over; the world ended. Jim overhears a clique talking about what they are going to do to someone. Plato warns Jim that they are laying for him. He points out a mansion where no one lives and suggests they go there. Jim watches Judy with the group. Buzz Gunderson (Corey Allen) pulls out a switchblade knife, and punctures a tire on Jim’s car. Jim takes off his coat and grabs a stick. They imply he is chicken, and he throws the stick away. Buzz tells them to give Jim a knife. He picks it up and puts it on the wall. Buzz is wearing a leather jacket and calls him chicken. Jim tells him not to call him that and starts to fight with the knife. Jim causes Buzz to lose control of his knife, and he gets him down. Buzz offers Jim the two knives and suggests another time. Jim says not with those, and they plan to meet at eight. An officer breaks up the group.
At home Jim washes his face and notices his cut shirt. He drinks milk from the bottle. He sees his father is wearing an apron and is cleaning up food he spilled before his wife sees it. Jim says to let her see it.
Judy kisses her father (William Hopper), and he tells her not to do that. Her mother comes in, and he says he is tired. When she kisses him, he slaps her. He offers to stay home, but she says it is not her home. She leaves the room, and he says he does not know what to do. Her mother says it is her age when nothing fits.
Jim is lying in bed, and his father comes in. Jim says he has to do something dangerous as a matter of honor. He asks his father what he would do. Frank says he would not make a hasty decision, and he sees Jim’s shirt is cut and shows blood. Frank offers to help him. Jim says he has to be a man. Frank says in ten years he will see how foolish he is now. Jim says he wants an answer now. Jim puts on a red jacket, grabs a piece of cake, and leaves in his car.
The teenagers gather on a mountain with their cars. Plato welcomes Jim and says he hitched there. Buzz comes over and takes Jim to his car. Judy asks Plato if Jim is his friend, and Plato says he is his best friend. Buzz flips a coin. Buzz tells Jim to try the door, and he practices jumping out. They look over the cliff and share a cigarette. Buzz tells Jim he likes him, and Jim asks why they are doing this. Buzz says they have to do something. They start their cars. The others organize their cars, and Buzz tells them to turn on their lights. He asks Judy for some dirt. Buzz says she will signal, and the first one to jump is a chicken. Jim asks her for dirt too, and she puts some in his hands. Judy stands in front and tells them to turn on their lights. She raises her arms. They rev their motors, and she lowers her arms. They speed past her driving next to each other. Buzz gets his sleeve caught on his door handle. Jim jumps out, but Buzz goes over the cliff in his car. The others tell Jim what happened and leave in their cars. Judy and Plato remain with Jim, who takes her hand. They get in his car.
Jim drops her at home, gives her a pocket mirror, and asks if she wants to see a monkey. He puts his car in the garage, and Plato invites him to come to his empty house. Jim goes in his house, and Plato writes down the address. Judy comes in and hugs her little brother. Her father sends Bo to bed. In her room she looks at the pocket mirror. Jim drinks milk from a bottle and lays down on a couch. His mother comes in and asks if he is all right. Jim says he wants to talk to his dad. He asks for a direct answer because he is in trouble. They heard about the bad accident. Jim repeats it was a matter of honor because they called him chicken. He tells what happened to Buzz. He says his father is not listening to him. Jim says he wants to go to the police, but his father tells him not to be idealistic. His mother does not want him to go to the police. Jim asks his dad if he told him to tell the truth. His mother says they are moving again. Jim says she will not use him as an excuse again. He says he wants to do something right. She says in ten years this will not matter. Jim asks his father to answer that, but he says nothing. Jim grabs his father and pushes him down. His mother says he will kill his own father, pulling him off him. Jim kicks a painting of his mother and runs out.
Jim goes to the police station and sees some kids coming out. He goes in and asks to see the detective, but he forgot his name. Jim says his name is Ray, but an officer says he is out on a call. The officer is booking someone. Jim calls Judy, but her father answers and hangs up. Jim comes back in his car, and Judy is outside and calls him Jamey. On the radio they hear that a song is dedicated to Jim from Buzz. Jim turns it off. Judy says they will be looking for him. He says he was chicken and jumped out. He recalls the morning and says he saw her, hoping it would be a beautiful day. She apologizes for being mean to him. He kisses her forehead, and she asks why he did it. Jim says he is not going back in the zoo. She says she is never going back. He says Plato told him about a place near the planetarium. He asks if she will go with him.
Plato rides his scooter, and three guys take him off and demand to know where Jim lives. They say his friend talked. They take his wallet. Plato goes in his room and looks at a letter about his father owing support. He gets a pistol and tells the maid that he has to warn him. The guys find Jim’s address.
Frank and Carol hear something and go down to the door. When he opens the door, a chicken is hanging down. He goes looking for Jim. Frank tells Carol he is not there. Plato arrives and asks where Jim is. He apologizes for bothering them and leaves on his scooter. Frank, Fremick, Judy’s father, and the maid are seen talking on the phone.
Plato finds Jim at the abandoned house. Plato says they think he told the police on them. Judy laughs. Plato comes in and lights candles. He asks how they like his castle. Jim asks Judy if she wants to rent or buy. Jim says they are newly weds. They cavort in the empty pool. Plato says he did not have fun there before because he was alone. Plato says he can remember because he went to a head shrinker. He says he is happy now. Judy asks where his father is, and he says he is dead, that he was a hero in the China Sea. Jim lays with his head in her lap, and she hums a lullaby. Plato is laying on the ground, and Jim covers him with a coat. Jim and Judy each take a candle, and they leave one with Plato. Three guys pull up and notice Jim’s car. Judy asks Jim if this is what it is like to love somebody. She says not running away is being strong, like being Plato’s friend when no one else liked him. She says it is easy now that she loves somebody. She tells Jim she loves him, and they kiss.
Plato wakes up and sees the three guys. He tries to run away but is trapped in the pool. He uses a hose as a whip. He runs away and hides, holding his gun. The three look for him. A police officer notices Jim’s car and calls in for help. Plato is crying and then shoots a guy on the stairs. Jim sees him, and Plato shoots in his direction. Jim asks what is the matter with him. Plato says he is not his father. Two police see Plato and chase him. Plato shoots at one. Jim and Judy hide in the bushes, and he kisses her. She says Plato was talking about Jim as a hero. Jim says he wanted them to be his family. The police are shooting, and Judy says they are killing him. Plato runs to the planetarium and breaks in. The policeman asks him to come quietly because he has not killed anybody yet. A police siren is heard, and three officers arrive. Fremick is driving Frank and Carol, and he says other kids are in trouble. They arrive at the planetarium. Fremick is told a kid has a gun and shot at an officer. Fremick uses a megaphone to talk to the boy inside. He tells him to drop his weapons and come out. Frank sees his son Jim and tells Fremick. Jim and Judy run inside. Police are instructed to hold their positions. Jim opens a door and says Plato can shoot him if he wants. Plato says he has a gun. Jim flips some switches on a control panel to show the stars. Plato asks if the end of the world will come at night. Jim asks Plato to stand up so that he can see him and talk to him. Plato comes up behind Jim and asks why he ran out on him. Jim says Judy is waiting, but Plato does not want to come out. Jim takes off his red jacket and gives it to Plato, who asks if he can keep it. Jim asks him to give him his gun. Plato says he needs it. Jim asks if he trusts him. Plato hands him the gun, and Jim takes out the clip of bullets. Plato asks him to give it back. Jim says the people there want him to be safe. He gives him the gun. Jim says they said he could bring him out. They start to leave, and Judy says hi. Plato says it is too bright. Jim calls out the door and asks Fremick to turn out the lights, and they will come out. Jim brings Plato out, but Plato says they are not his friends. Jim puts his hands up and walks down the stairs. They turn on the lights. Plato runs out with the gun, and they shoot him. Jim says he has the bullets. Jim cries and asks why they did it. He clings to his father and asks him to help him. Frank says he will help him and tells him to stand up. They both stand up. The maid says the poor baby has nobody. Jim zips up the jacket and says Plato is always cold. Medics put him in an ambulance. Jim walks with Judy, and Carol smiles at Frank. The cars drive away.
This realistic melodrama portrays a troubled generation of youths who have cars but seem to be lost and out of touch with their parents’ society. The scientific view of the immense universe in which humans are of little consequence alienates their sense of reality and purpose in life. Yet despite the other casualties, Jim and Judy seem to have found a love for each other.