The story is set in a run-down, post-industrial area of Salford. Jo (played by Rita Tushingham) is a 17-year-old schoolgirl, with a self-centred, 40-year-old mother with a drink problem, Helen (Dora Bryan).. After a fall while walking past the Manchester Ship Canal, Jo meets a black sailor called Jimmy (Paul Danquah) who invites her onboard his ship to attend to her grazed knee. The two accidentally meet again and start a brief romantic relationship, but Jimmy's ship soon sails and they part. Relations between Jo and her mother become further strained when her mother courts and marries a self-made businessman, Peter Smith (Robert Stephens).