Jennie Jones, Janet Munro, is a beautiful woman who returns intoxicated to her London apartment late one night and begins to destroy its contents in a rage, tossing her purse, keys, and expensive gowns out into the street. The story then unfolds in flashback, tracing her life from a struggling, economically depressed Welsh town to the lure and risk of a glamorous, uncertain future in the capital.
As a young girl, Jennie grows up in a former mining town in Wales, working in her father’s shabby general store and dreaming of something brighter. The store struggles, and Jennie is horrified when her father suggests she move to Cardiff to live with elderly aunts as a companion and caregiver. In Cardiff, Jennie and her friend Violet meet two well-off older men, Andy and Rex, who take the girls to a fashionable bar and club for drinks and dancing. Jennie drinks heavily and passes out in Andy’s car, a moment that foreshadows the precarious path she will tread.
She wakes up naked in bed in a man’s apartment in London, having lost her virginity while drunk, and she finds herself estranged from her father for staying out all night. She goes to meet Andy at a London pub, but he does not appear. The kindly barman, Bob Williams, John Stride, offers her help and hospitality, a gesture that Provokes tension with the barmaid Ella, Anne Cunningham, who is drawn to Bob. In a desperate bid for security, Jennie tells Bob that she is pregnant and accepts his offer to move into his flat, living on his wages with the hope of marriage on the horizon.
But Jennie grows restless and bored. She accepts an invitation from Karl Denny [Alan Badel], a renowned producer and her neighbor, to attend a party with the aim of finding work as a model or actress. She convinces Bob to lend her a large sum to buy a proper party dress, signaling a shift from seeking stability to chasing opportunity and status. Denny notices Jennie at the party and asks to see her the following night, ostensibly about an acting role.
After the party, Jennie creates a disturbance when she returns drunk to Bob’s apartment. The next night, she fails to keep her appointment with Denny. Bob goes to Denny’s apartment to find her, and they argue; Jennie reveals that she is not pregnant, does not love Bob, and does not want to marry him. Heartbroken, Bob leaves, and Jennie becomes Denny’s mistress, drawn deeper into a world of nightlife, pretense, and emotional risk.
The film returns to the present, where Jennie’s morning-after rampage is revealed as the moment of her death. She has overdosed on pills, and the wreckage of her flat is scattered with reminders of how far she had drifted. Her address book, filled with numbers from various men, suggests a pattern of promiscuity. The ambulance carrying Jennie’s body almost collides with Bob and Ella, who are now a contented couple, oblivious to the tragedy that ended Jennie’s life.
