It is not practiced perfection that hits the right note in Ian McEwan’s most recent novel but the gloriously amateur, both in the life of his protagonist and the flow of McEwan’s prose. The novel hinges on the way in which the family court deals with the most painful and intimate things in life, centring on disputes over religion and love from the guarded perspective of the legal system that presides over such sensitive ground.

From the outside McEwan’s Fiona Maye has it all: money, culture, friends. A high court judge married to a professor of ancient history, she’s part of a world that is obese with its own wealth and cultural appetite. She’s able to mournfully play the piano to her society friends and yet — as McEwan shows — the only real joy from music and culture of any kind comes at a point of pure and accidental connection in the confines of a hospital ward.

McEwan is at his strongest when describing the weariness of a London street, the emotional haunting of a piano concerto, the painful tugs of memories caught within people, places and objects. His sentences fluidly move in the imagination, taking us in and out of characters and from scene to scene in familiar tones as he guides us through the pained legal processes in which law and love painfully clash. The only danger comes at points of nervous regurgitation; research remains a fundamental part of McEwan’s method and for a novel such as Saturday the fruits of this labour pay off handsomely. However in The Children Act this effort appears laborious, you can see the effort to make everything ‘authentic’ bursting at the seams, in his overzealous attempts to remain true to ‘facts’ in polemical moments, McEwan actually puts himself in danger of losing the thread of his own fiction, and becoming lost in reportage.

Maye is impenetrable, painfully withdrawn from her own life, a protagonist who remains sadly unsympathetic and caricatured, and this weakens the novel as a whole. The one good and unexpected thing she does — ironically — she bitterly regrets. Like a practised musician, McEwan is adept at pleasing an audience, and his writing here seems to echo the well-rehearsed music of his heroine. What we miss, perhaps, is the liveliness and sense of risk of some of his earlier novels; this is fluent and pleasing writing, but there is a sense in which it lacks the passion of live performance, lacks the very energy which McEwan appears to praise and point towards at the finest moments of this novel.