There is an incidental link between this novel and Greene's earlier A Gun for Sale (1936), in that the murder of the gang boss Kite, mentioned in A Gun For Sale, allows the seventeen-year-old sociopath Pinkie to take over his gang and thus sets the events of Brighton Rock in motion.[2] The murder of Kite had been brought about because of a report by Charles "Fred" Hale in the Daily Messenger about his slot machine racket. Now Hale has been sent to Brighton to distribute cards anonymously for a newspaper competition and realises that he is being hunted by Pinkie’s mob.
Hale meets middle-aged Ida Arnold by chance in a pub and then on the Palace Pier as the mob is closing in, but he is snatched away without her realising what has happened to him. To confuse the police investigation, Pinkie has gang member Spicer distribute Hale's cards about the town and then tries to retrieve one card from the café in which sixteen-year-old Rose is working as a waitress. Since Rose had spotted Spicer leaving the card, Pinkie realises that she can now disprove his trail of deception and must take measures to prevent this. He therefore courts Rose until she falls in love with him, his aim being to marry her so that she cannot testify against him. In reality he looks down on her, since she comes from the same socially deprived neighbourhood as himself, and is even repelled by her physically.
Back in London, Ida reads about the inquest on Hale's death, which had found that he died of heart failure. Remembering the state of terror that Hale was in when she last saw him, she decides to go down to Brighton and discover the full story. While there she recruits the help of one of her old bed-fellows and manages to finance her trip with a lucky bet at long odds. Her enquiries soon establish the broad outlines of the story, even though Rose consistently refuses to co-operate and warns Pinkie of Ida's investigation.
Pinkie is summoned to an interview with Colleoni, a leading mobster whose aim is to take over all the illegal operations in Brighton. At the time Pinkie is too cocksure to take up Colleoni's invitation to join his operation. Afterwards he pretends to have reconsidered in order to get Colleoni to murder Spicer, whom Pinkie suspects of being close to turning informer. In fact both men are set up for a razor attack at the horse races but escape separately. Discovering that Spicer is still alive, Pinkie throws him to his death from an unstable staircase in their lodgings and implicates their terrified solicitor Prewitt[note 1] into helping him cover up the murder.
Prewitt has also helped Pinkie and Rose avoid the legal obstacles to their marriage and Pinkie now discovers that Rose has known of his criminality all along but not minded. Feeling trapped, and with what remains of his gang disintegrating, Pinkie proposes a suicide pact to Rose, on the pretence that Ida is close to having him arrested by the police. His plan is to get her to shoot herself at the developing resort of Peacehaven but not to fulfil his part of the pact. Ida meanwhile has tailed them, sensing that Rose may be in danger, and has brought a policeman along with her. Pinkie's attempt to throw vitriol at his attackers misfires and, blinded by it himself, he runs over a cliff to his death.
Rose later goes to confession and explains to the priest that she had wanted to accompany Pinkie even into damnation. She is told that since Pinkie had loved her, then there was good in him and she might become the means for his ultimate salvation. She leaves, looking forward to playing a recording he made on the day of their marriage, not realising that it really contains the declaration of his hatred.
