Martin Lynch-Gibbon is a 41-year-old well-to-do wine merchant whose childless marriage to an older woman called Antonia has been one of convenience rather than love. It never occurs to him that his ongoing affair with a young academic called Georgie could be immoral. Displaying quite a number of macho attributes in his relationships with women, Lynch-Gibbon is shocked when, out of the blue, his wife tells him that she is going to leave him for Palmer Anderson, her psychoanalyst and a friend of the couple's, with whom she has had a secret affair for quite some time. Lynch-Gibbon moves out of their London house but still does not want to publicize his affair with Georgie, let alone become engaged to her.

At roughly the same time Cupid's arrow hits Lynch-Gibbon again. This time he falls for Honor Klein, Anderson's stepsister, who is a lecturer in anthropology at Cambridge, a woman who, on seeing her for the first time, he remembers finding rather repulsive. Like a man possessed, he follows her to Cambridge and, in the middle of the night, breaks into her house, only to find her in bed with her stepbrother. When, shortly afterwards, Antonia confesses to him that she has also been sleeping with his older brother Alexander ever since he introduced them to each other ("You mean you didn't know at all? Surely you must have guessed."), Lynch-Gibbon's world starts disintegrating. Despite his being a wine merchant, he chooses whisky as his constant companion. In the end, however, he realizes that life must -- and somehow will -- go on.

In A Severed Head, Murdoch succeeds in presenting a middle-aged bourgeois who initially thinks of himself as a survivor but realizes that he is in fact a victim. Throughout the novel, all the main characters insist that they have long overcome conventional morality, that they are free agents in the truest sense of the word, but in spite of his hedonism Lynch-Gibbon's residual moral posture just will not go away. Murdoch is particularly good at conveying the atmosphere of benevolence and the apparent lack of hard feelings among the individuals that have wronged and been wronged. ("It is not at all our idea that you should leave us. In a strange and rather wonderful way we can't do without you. We shall hold on to you, we shall look after you," Anderson says to Lynch-Gibbon, who sees himself as a cuckold rather than anything else.) At times funny, sad at others, A Severed Head also deals with more serious issues such as abortion (Georgie terminates her pregnancy at an early stage of her relationship with Lynch-Gibbon) and attempted suicide (again it is Georgie who tries to take her own life after being rejected by both Lynch-Gibbon and his brother).

Despite these serious overtones, A Severed Head is regarded by many readers as the most entertaining of Murdoch's novels. As British novelist William Sutcliffe put it, "Of all the lots-of-people-screwing-lots-of-other-people novels this is probably the best, and certainly the weirdest. With less philosophising and more shagging than Murdoch's other books, it is a joy to see this wonderful writer let her hair (and her knickers) down.

Together with J. B. Priestley, Murdoch adapted her book for the stage. After four previews, the Broadway production, directed by Val May, opened on October 28, 1964 at the Royale Theatre, where it ran for only 29 performances. The cast included Robin Bailey and Jessica Walter.