Brighton, between the wars. A journalist going under the name of Kolley Kibber arrives in town on a promotional campaign for the Daily Messenger, offering a prize to anyone who can identify him from his photograph. He is recognised by members of a local gang who know him as Fred Hale and hold him responsible for the death of their leader, William Kite. Hale is confronted in a bar by the gang's new leader, seventeen-year-old Pinkie Brown, with his henchmen Dallow and Cubitt. They pursue him through Brighton, and eventually Pinkie kills him on the fairground ghost train.
To establish an alibi, Pinkie has another of his henchmen, the elderly Spicer, continue to distribute Hale's 'Kolley Kibber' cards after his death. When Spicer places one of the cards in a café, Pinkie fears that he will have been remembered, and goes to the café himself. The young waitress, Rose, confirms that the customer who left the card was not the man in the photograph, so to gain her confidence and keep her quiet Pinkie asks her out on a date.
He tells Rose not to answer any questions about Hale or the man she saw in the café, warning her that women who get involved in such matters risk losing their looks. When he returns to the lodging house he shares with the rest of the gang, he overhears Spicer complaining about his leadership.
A rival gang, larger and more powerful, is becoming a threat to Pinkie. He visits its leader, Colleoni, who patronises him and sends him away. Pinkie is then taken to the police station, where he is cautioned against instigating warfare between the gangs and advised to leave Brighton.
Meanwhile, Ida Arnold, an entertainer appearing in the Pierrot show, spent some time with Hale on the day of his death, and is convinced that the circumstances are suspicious. After speaking to Rose, she visits the police and, when the inspector insists that he died of heart failure, decides to conduct her own investigations.
Pinkie begins to regard Spicer as a liability, and sends him to the races the next day to be killed by Colleoni's men. In the event, both Spicer and Pinkie are attacked with knives, and make their way separately back to the lodging house. Discovering that Spicer is still alive, Pinkie pushes him over the banisters and he falls down the stairwell to his death.
Rose is now in love with Pinkie, and he decides to marry her so that she will not be able to give evidence against him. With the help of a corrupt lawyer named Prewitt, a hurried registry office wedding is arranged. Afterwards, Rose asks Pinkie to record his voice for her in a fairground booth, and while doing so he confesses that he hates her.
Ida hears of Spicer's death and, realising the truth, goes to see Rose, posing as her mother. Pinkie returns in time to see Ida leaving and, when Rose also claims that the visitor had been her mother, he resolves to kill her by pretending to enter into a suicide pact. Colleoni offers Pinkie £300 if he and his gang will get out of Brighton, and Dallow learns that Ida has also decided to leave, having no evidence against them.
Pinkie takes Rose for a walk on the pier and tries to persuade her to shoot herself. To save Rose, Dallow joins forces with Ida and the police to arrest Pinkie, who falls off the pier to his death. Rose later plays her record: it has been damaged when Pinkie had tried to destroy it, and the needle sticks on the words "I love you".
