The book begins with a quotation from Henry James, "Never say you know the last word about any human heart." A short preface (an anonymous editor suggests it was written in 1987) explains that the earliest pages have been lost, and recounts briefly Mountstuart's childhood in
Montevideo,
Uruguay, before he moves to England aged seven with his English father and Uruguayan mother. In his final term at school he and two friends set challenges. Logan is to get on to the school's first XV
rugby team; Peter Scabius has to seduce Tess, a local farmer's daughter; and Ben Leeping, a lapsed Jew, has to convert to
Roman Catholicism. Mountstuart enters Oxford on an
exhibition and leaves with a third in History. Settling in London, he enjoys early success as a writer with ''The Mind's Imaginings
, a critically successful biography of Shelley; The Girl Factory
, a salacious novel about prostitutes (which is poorly reviewed but sells well); and Les Cosmopolites'', a respectable book on some obscure
French poets. Mountstuart's mother loses the family wealth in the
Wall Street crash. He embarks on a series of amorous encounters: he loses his virginity to Tess, is rejected by Land Fothergill whom he met at Oxford, and marries Lottie, an Earl's daughter. They live together at Thorpe Hall in Norfolk, where Mountstuart, unstimulated by slow country life and his warm but dull wife, becomes idle. He meets Freya whilst on holiday, and begins an affair with her. Just before he departs for
Barcelona to report on the
Spanish Civil War, Lottie unexpectedly visits his London flat and quickly realises another woman lives with him. On his return to England, following an acrimonious divorce, he marries Freya in
Chelsea Town Hall. The newlyweds move to a house in
Battersea where Freya gives birth to their daughter, Stella. During the
Second World War, Mountstuart is recruited into the
Naval Intelligence Division by
Ian Fleming. He is sent to Portugal to monitor
the Duke and
Duchess of Windsor; when they move to
the Bahamas, Mountstuart follows, playing golf with the Duke and socialising regularly until the murder of
Sir Harry Oakes. Mountstuart suspects the Duke is a conspirator after two hired detectives ask him to incriminate Oakes' son-in-law with false fingerprint evidence. Mountstuart refuses and is called a "
Judas" by the Duchess. Later in the war, Mountstuart is interned in
Switzerland for two years. After the war's end, he is grieved to discover that Freya, thinking him dead, had remarried and then died, along with Stella, in a
V-2 attack. Mountstuart's life collapses as he seeks refuge in an alcoholic daze to escape his depression. He buys 10b Turpentine Lane, a small basement flat in
Pimlico. He returns to Paris to finish his
existentialist novella,
The Villa by the Lake, staying with his old friend Ben Leeping (now a successful gallery owner). After a failed sexual encounter with Odile, a young French girl working at Ben's gallery, he attempts suicide but is surprised by the girl when she returns an hour later for her
Zippo lighter. Ben offers Mountstuart a job as manager of his new gallery in New York, "Leeping fils". Mountstuart mildly prospers in the art scene of the 1960s, meeting artists like
Willem de Kooning (whom he admires) and
Jackson Pollock (whom he does not); he moves in with an American lawyer, Alannah, and her two young daughters. On his return to London, he has an affair with Gloria, Peter Scabius' third wife (Peter has become a successful author of popular novels), and in New York with Janet, a gallery owner. He eventually discovers Alannah having her own affair, and the couple split. He reconciles with his son from his first marriage, Lionel, who has moved to New York to manage a pop group, until Lionel's sudden death. Monday, Lionel's girlfriend, moves into Mountstuart's flat; at first friends, they become intimates until her father turns up and Mountstuart discovers – to his horror – that she is 16 (having told him she was 19). His lawyer advises him to leave America to avoid prosecution for
statutory rape. In the African journal, Mountstuart has become an English lecturer at the
University College of Ikiri in
Nigeria, from where he reports on the
Biafran War. He retires to London on a paltry pension and, now an old man, he is knocked over by a speeding post office van. In hospital he brusquely refuses to turn to religion, swearing his atheism and
humanism to a priest. He recovers but is now completely destitute. To boost his income and publicise the state of hospitals, he joins the Socialist Patients' Kollective (SPK), which turns out to be a cell of the
Baader-Meinhof Gang. He becomes the SPK's prize newspaper seller and is sent on a special mission to the continent. The trip ends with a brief interrogation by Special Branch, after which Mountstuart returns to his life of penury in London. With a new appreciation of life, he sells his flat and moves to a small village in the south of France, living in a house bequeathed to him by an old friend. He fits into the village well, introducing himself as an
écrivain who is working on a novel called
Octet. As he contemplates his past life after the deaths of Peter and Ben, his old school friends, he muses: == Themes ==