No matter which name Philip Roth chooses for his narrators or fictional alter egos, whether it is Nathan Zuckerman, David Kepesh or indeed even, slyly, Philip Roth, they invariably share many of the same urgent preoccupations: the tyranny of sexual desire, the essential incomprehensibility of women, the question of Jewish identity and self-positioning, literary ambition. In other words, they are all recognisably the same man: “Roth Man”, as Martin Amis once called him. Roth Man has long been defined by his egoism, his limitless ambition, his aggressive and relentless sexual energy, his scabrous wit and irony, and his rage.

More recently, Roth’s novels have been suffused with a sad music. They are soaked through with illness and regret. For Roth Man is now old; his friends have died or they are sick and dying; the desires of the flesh remain, but the flesh itself is withered.

No one has suffered the torments of old age more than Nathan Zuckerman, who made his first appearance in Roth’s fiction in The Ghost Writer (1979). In that novel the young Zuckerman found a potential mentor in E.I. Lonoff, an acclaimed short story writer and fellow Jew, his hero and inspiration. He entered Lonoff’s life at a time of great complication for the older man. Long married to a decent and honest woman, Lonoff had fallen in love with one of his students, Amy Bellette, about whom Zuckerman fantasised feverishly.

Exit Ghost begins with Zuckerman, now 71, returning to New York after more than a decade’s absence from the city. He has been living in austere solitude on a remote hilltop in the Berkshires, doing little but writing, reading, and listening to music. Surgery for prostrate cancer has left him both impotent and incontinent, as readers of Roth’s acclaimed “American Trilogy” - American Pastoral (1997), I Married a Communist (1998), The Human Stain (2000) - will know. These novels were narrated by Zuckerman but they were not about him; he was a mere facilitator used by Roth to tell other people’s stories. Now, in regretful old age, Zuckerman is writing about himself again, and, in spite of his long retreat from the world, his refusal to read newspapers or watch television news, he finds himself succumbing once more to what he calls the “stimulants, temptations, and dangers of the present moment”.

He is in New York to see a doctor who has devised new techniques to counter the debilitating effects of prostrate cancer. He is soon distracted, first by a chance encounter in a diner with an aged and deathly Amy Bellette, and then by deciding, on a whim, to respond to an advertisement for a house swap that would enable him to live for a year in Manhattan. This impulsive decision brings him into contact with an affluent young couple - both aspirant writers - Billy and Jamie. As it happens, a young male Harvard friend of theirs is writing a biography of Lonoff. We are told that he spent the last years of his life blocked while unhappily labouring on a novel that was never published.

Zuckerman becomes predictably obsessed with Jamie, reawakening in him a furious sexual yearning that can never be fulfilled. He conducts imaginary dialogues with her, as he did with another young, sexy woman in an earlier novel, The Counterlife (1986). Here the dialogues offer a counter-narrative of sexual fulfilment, contrasting with the bleak actuality of Zuckerman’s plight: an old man, sick with desire and futile longing, moving slowly to the final exit door of his life, unsettled by spectral presences from his past, and envious of the health and vitality of those such as the biographer who are on their way up just as Zuckerman is on his way out. The set-up is poignant.

There is much to admire here, not least the acuity of observation - the cocky and aggressive biographer, whom Zuckerman meets for the first time in Central Park, is “savage with health, and armed to the teeth with time”. But too much is too hastily told or compressed; detail, nuance, and the careful colouring of scenes are sacrificed as characters offer long, unbroken summaries of their lives, their talk looping and sprawling. The imaginary dialogues feel this time like an unearned extravagance, and Roth assumes too much knowledge of his readers - that, for instance, they know all about Zuckerman.

So this is a novel for those who already know the novels of Philip Roth. It is a coda, and a farewell - to Nathan Zuckerman, but also to all those readers who have followed him on his long journey through Roth’s inflamed fictional landscape.