At Ted's coffee bar, Frank and his friends Ron and Ginger drink and flirt with the girls who dance to the jukebox music. Frank provokes a black young man who comes in and flirts with the waitress Frank is fond of. Calling him 'spade' and 'filthy black face', Frank soon loses control and gets into a fight with the black man, who flees. Frank and his friends chase him through the dark streets of London. They corner him in front of a garage by an alley but, as they are ready to attack, a young woman drives her car into the garage just in time to scare Frank and his gang away. As she tries to open the garage door, the black man offers to help and she invites him to her flat for a coffee.

Frank returns home and as he goes to bed he promises to himself that he will get the 'black spade' the next day. In the meantime, his father, Pop, is in the shade looking after his rabbits, including a black one which he calls 'nigger'.

The next night, Frank gets a bicycle chain and goes 'nigger-chasing' with his gang. By a park, they beat up a black boy and injure his white girlfriend, making their escape before the police arrive. Frank runs back to the house and hides the bicycle chain in the cupboard under the sink. When his father returns they argue about Frank's inability of unwillingness to find a job; Frank blames black immigrants for 'sponging off' the country and Pop worries that he won't be able to support his son financially for much longer.

In the meantime, Josie, Frank's sister, is late for dinner and as the family wonder where she might be, Sergeant Parker visits to report that she's had an accident. She and her boyfriend were attacked in an alley by a park; she has a cut on her face with a bicycle chain, while her boyfriend, a 'coloured' boy, was hit with a metal pipe and is in hospital. In a conversation with Pop and Frank about the problem of juvenile delinquency and 'colour' prejudice, Sergeant Parker realises Frank's hatred for black people but has no other evidence that the young man was involved in the attack.

The accident causes friction and divides the family. Pop's wife, Gladys, is terrified of the idea that her daughter may be going out with a 'coloured' boy, whereas Pop defends his Josie's choice and criticises his wife for talking like 'those stupid hooligans'. In an argument with his sister, Frank gives away information about the location where the attack took place, raising Josie's suspicion of his involvement. He openly expresses his prejudice and, as his temper rises, takes out his knife, threatening to kill the 'nigger'. When Pop tries to intervene, Frank gets the bicycle chain out of the cupboard to attack him but is stopped by Gladys. All now realise that Frank was involved in the attack.

Back at Ted's café, Ginger delivers the news that the black boy they beat up is dead. Frank and his friends rush to dispose of the incriminating evidence - the metal pipe. Gladys is willing to cover up for Frank, and hides the bicycle chain. Pop refuses to be complicit in the cover up and, when Josie overhears her mother's plans to help Frank escape, she - with Pop's silent consent - makes a phone call to turn her brother in to the police.

When the police arrive, Pop is in the shade holding his 'nigger' rabbit in his hands and reassuring it that the police have not come to get it.