Dave has just moved to London from Jamaica to study and be with his mother, Mrs Jordan, who runs a social club for her fellow countrymen in Brixton. Before he heads off to Cambridge University, Dave starts seeing Terry, a young working-class English woman. Mrs Jordan is mortified when she finds out; all her hard work has been directed towards offering her son the best education to help him rise to the ranks of high-class society and avoid the pitfalls of a class-blind racism.

Dave, however, is excited about Terry and goes to meet her family - her mother and her brother, Georgie - one evening before they go out. Although he is disappointed to find out that Terry is only a cleaner in a factory, that he can hardly understand her mother's cockney accent and that he does not share the same views on cultural and social matters with Georgie, he still falls for her.

As Dave prepares to leave for Cambridge, Terry's family wonder whether her relationship is going to last, and worry about her being hurt. Georgie thinks that Dave's interest in his sister is only sexual and, when Dave pops in to say goodbye to Terry, treats Dave badly, upsetting him and shaking his trust in Terry by suggesting that she's been 'mucking around'. Dave runs away and when Terry visits him to give him a going-away present, they row. But the argument is soon over, and only serves to strengthen their love.

A few months later, Dave is back in London during a university break. He talks to his mother about his experiences at Cambridge and the different kind of people he met there. He mentions a middle-class English woman, Jill, who gave him a lift from Cambridge to London when he missed the bus, and talked about a forthcoming party, to which she neglected to invite him.

Terry arrives to welcome him back but, as the couple rejoice in being together again, they are interrupted by Mrs Jordan, announcing the arrival of Jill, who has come, she says, to ask him to remind her of a Jamaican lullaby he sang on the way from Cambridge. Dave introduces Jill to Terry, who is intimidated by her class. As Jill leaves, she invites Dave to the party.

Terry is jealous of Jill, while Dave blames Terry for showing him up in front of Jill and starts to doubt his feelings for her. He thinks that he should not be held back by a girl from the 'gutter'. This would only confirm Jill's suspicion that his colour goes with Terry's cockney accent and her low class. Terry leaves, upset.

Dave goes to Jill's party and becomes the centre of the attention. Some of Jill's white, middle-class friends are impressed with his singing skills and want to know more about the country he comes from; others think that he should be their butler. He flirts with Jill and when the party is over they go back to his house. Dave admits that Terry was his girlfriend but now he wants to level with the best. But soon after he and Jill finally kiss, Terry turns up. Despite his mother's hostility, Dave agrees to talk to her. He apologises for hurting her, and eventually admits to himself and to Terry that she is the one he loves with his heart and his mind.