Stratford, East London. 17-year-old welder's apprentice Del Walker is part of a gang of aimless East End youths. They break into a café and make off with a small booty of cakes and loose change. Del buys a cinema ticket and then lets his friends in through the back door. After the film they rough up an accomplice of their local rival, Parker. Later, at their hideout, they excitedly receive news that an old gang member, Jo "Bronco Bullfrog", is out of borstal.

At the local café, Del encounters Irene Richardson, who makes an immediate impression on him. After buying a new motorbike with money from his father's competition winnings, Del, accompanied for moral support by his friend Roy, rides out to Irene's flat to ask her on a date. Afterwards, Del and Roy retire to a nearby café, where they meet Bronco Bullfrog, who invites Del to help him with a planned robbery at a railyard later in the week.

Del takes Irene to the West End. They can't afford a cinema ticket, so go to a nearby Wimpy Bar. When Del calls round for their next date, it becomes clear that Irene's mother doesn't approve of him, but Del and Irene go to his house. Del's father says he doesn't want her there so the youngsters leave, dismayed that they've nowhere to go. They start to bicker and Irene goes home.

Del and Roy help Bronco with the railyard break-in, making off with electrical goods. Later, they receive a cut of the proceeds. Roy is attacked by Parker and an accomplice. Del and Irene visit him in hospital. Sergeant Johnston calls at Del's house and implies that he was responsible for the attack. Del's father is annoyed and blames Irene as a bad influence.

Del's friend Chris suggests that he and Irene go to the country to Del's aunt's place, where Del could get work and they could be together. Because of increasing parental pressure and disapproval, Del and Irene decide to run away to the country. Irene's mother reports her missing and tells Sgt Johnston that Del is the culprit. Del and Irene call at his uncle's. He thinks they are just visiting for the day but Del asks if they can stay. Del's uncle says there is no work in the area and, dejected, Del and Irene return to London.

They call on Bronco at his flat (still full of the electrical goods from the heist), where they finally get to be together for the night. The following morning Del decides to go and see Grimes, his boss, for advice. Grimes says he should go home before he's charged with abduction and gets a criminal record, telling him to be back at work by lunchtime. Del sets off to tell Irene. However, his motorbike gets run over by a lorry and he is then set upon by Parker in the Blackwall tunnel as he makes his way back.

At Bronco's flat, a badly beaten Del tells Irene that they should go home. She is upset but agrees. Sgt Johnston calls and tries to apprehend Del and return Irene to her mother. He is attacked by Del and Bronco and the three then run away. Del realises that there's nowhere to go and decides to wait with Irene for the police. Bronco, however, having been caught with all the stolen goods at the flat, does not want to hand himself in and decides to take his chances and keep running.