In July 1962, Edward Mayhew, a graduate student of history, and Florence Ponting, a violinist in a string quartet, are spending their honeymoon in a small hotel on the Dorset seashore, at Chesil Beach. The two are very much in love despite being from drastically different backgrounds.
During the course of an evening, the couple reflect upon their upbringing and future prospects. Edward is sexually motivated and has a taste for rash behaviour. Florence is bound by the social code of another era and, perhaps having been sexually abused by her father,[3] is terrified of sexual intimacy. She tries to mentally prepare herself for the inevitable consummation, but the thought continues to repel her.
Just as the couple are about to have sex for the first time the inexperienced Edward involuntarily ejaculates onto her belly and thighs. Revolted, Florence runs out of the hotel and onto the beach. Edward follows and the couple argue, with Florence making it clear that she will never agree to have sex. Edward accuses her of lying during their marriage vows, and is further angered when Florence suggests that he could sleep with other women to relieve his sexual desires. The couple separate, and their marriage is annulled for lack of consummation.
Decades later, Edward reviews his subsequent life. A year after the annulment, ruminating on Florence's suggestion that he could sleep with other women, he realises that he no longer finds it to be insulting, though he remains unwilling to re-connect. Losing interest in writing history books, he becomes a shop manager. After his mother's death, he moves back to his childhood home to take care of his ailing father. He recalls enjoying good relationships with his friends and family, and exploring other romances including a brief marriage with another woman, while acknowledging that he had never loved anyone as much as he loved Florence.
She, meanwhile, has been enjoying critical and commercial success with her string quartet, though Edward does not attend any performance and avoids even reminders of it, unaware that Florence thinks of him after every performance. Edward chooses not to make contact, preferring to retain his early memories of her.
In his sixties, Edward recalls once again the night that he and Florence separated, wondering what could have been. He concludes that he and Florence would have enjoyed a loving and happy marriage, that Florence would have been beneficial to his career success, and that with love and patience he might have helped her to open up and enjoy sex. He muses that one's life can be changed by simply doing nothing: Florence had loved him deeply as she had walked away, and wanted nothing more than for him to call out so that she could turn back to reconcile. The novel ends with Edward remembering the sight of Florence walking away along the beach before disappearing from his sight.
