THE CHILDREN ACT By Ian McEwan, Jonathan Cape, Rs 599

Ian McEwan has a passion for thorough research, the results of which he is wont to weave into his novels, to make or mar them - usually to mar them. From neurosurgery, genetics, psychiatry to climate change and espionage, McEwan has mastered them all. In The Children Act, it is the turn of family law, which McEwan examines in its minutiae, to reveal its liberal-hearted expansiveness as well as its dark holes, where its fails to cover the unique challenges that life may yet throw up. Mercifully, in The Children Act, the research works, although it does also yield a few dispensable pages. Indeed, The Children Act can be counted among McEwan's more likeable novels, of which Atonement (2001) is one. And The Children Act is moving for much the same reasons that had made Atonement touching - it unforgivingly unravels the vulnerable self of a person who has judged and sentenced others. The protagonist of The Children Act, Fiona Maye, is a renowned high court judge who presides over cases in the family court. Her 60-year-old mind is crisp and cold, like the 13-year-old mind of Briony Tallis from Atonement. And, for Fiona as for Briony, there is no expiation of guilt for what they have done. They must live out the sorrow of their defeat in the face of disordered life, as the structures they have lived by - whether of the novel or of law - collapse for them as a result of a moment's surrender to temptation. In the absence of religion to offer consolation, the older Briony could seek atonement in writing a novel where she gives the lovers separated in real life by her childish judgment a happy ending. For Fiona, there is only waste: sad time stretching thereafter.

The conclusion is surprising in the McEwan canon since it goes against the smugness his main characters often display. And Fiona is also not the cauldron of vice, ripe for punishment, as McEwan's disgusting anti-hero in Solar (2010) had been. In fact, Fiona, of whom it is remarked by an admiring chief justice, "'Godly distance, devilish understanding, and still beautiful"', must be close to McEwan's idea of himself. Speaking of her, McEwan had confessed in an interview, "I gave her lots of me, from my toenails [Fiona's are described as having "fungal streaks"] to her love of rational discourse - and attempts, often thwarted, to bring it into human affairs." In the same interview, McEwan talks of a dinner with a community of judges in the course of which he had thought, hearing the teasing banter that went around the table, "My God, this could be a group of novelists." The coming together of "God", judges and novelists is telling, since the people belonging to the last two categories often take upon themselves to stand in for the first, who remains the most powerful fictitious character ever invented.

The convergence of the three is the idea McEwan explores here - Fiona, trying to re-form life through words from her high chair, is both god and author. After passing a particularly sensitive judgment involving a pair of Siamese twins (named Mark and Matthew), one of whom must live at the cost of the other, Fiona starts losing the balance she had so long identified herself with: "She was the one who had dispatched a child from the world, argued him out of existence in thirty-four elegant pages." The guilt of having cancelled out a body makes her want to lose her own corporeality. Exactly seven weeks and a day after the verdict, her husband, Jack, declares that he wants to have a last chance at attaining sexual ecstasy, with a younger woman, because Fiona would not give it to him anymore. Fiona knows, but Jack doesn't, that her physical withdrawal dates from the day of the judgment on the twins. In her injured pride, she would not explain the predicament to Jack in an effort to exonerate herself.

The drama between husband and wife, brought out with chilling and amusing accuracy, is the best part of the novel, rather than the belief versus reason debate, which gets the author's high-minded attention. However, to grant it to McEwan, the two are interlinked, with the personal catastrophe setting off the crisis of reason. Getting inside Fiona's ordered mind, scattered by the cross-currents of anger, helplessness, culpability, despair and longing, McEwan records the ebbs and flows in her ratiocinative process, where each step forward only serves to hurl her back to the still point of the fact that she has been rejected for another woman after 30 years of marriage. "She had the power to remove a child from an unkind parent and she sometimes did. But remove herself from an unkind husband? When she was weak and desolate? Where was her protective judge?"... "If he stayed, humiliation, if he left, abyss."... "He had not troubled himself to deny [the affair], and she was not going to ask again. It was not only pride. She still dreaded his reply." And all this from a woman who, having come of age at the time of the sexual revolution, is expected to find only banality in infidelity. Fiona's vulnerability brings the honoured judge of the family court to the level of a child. It is a mortifying situation to which the author will give a pitiless twist when Fiona will fail to respond to the appeals of a child - whom she had saved from death by parental religion with her judgment - to grant meaning to his new life of lost faith.

The novel begins to sag as soon as the author leaves behind the frisson between Fiona and Jack to concentrate on this terminally ill boy, who is about to enter the blasted heath of adulthood. McEwan is at pains to establish the exceptionality of this adolescent, Adam Henry. He plays the violin from his hospital bed, writes Blake-ish poetry, argues cogently about god and faith, and is beautiful beyond measure - looking at him, Fiona "wondered if this was what her mother would have called an old-fashioned face... Everyone's notion of the face of a Romantic poet, a cousin of Keats or Shelley." The point sought to be made is his otherworldliness, which would justify both his initial decision to die for his parents' beliefs and his later, equally urgent, need to be 'justified' by Fiona, on whom he transfers his dependence once she has proved to him the pointlessness of his parents' stance.

But McEwan overstates his case and risks making a wide-eyed, rosebud-lipped puppet out of Adam - a "sweet boy" who can only be meant for death. His role is to shatter Fiona's self image as a lady with a perfectly symmetrical mind, and once he has done that, he is made to fade away rather unceremoniously, to leave the stage to Fiona again. Jack comes back to her life upon realizing his stupidity, but the Fiona transformed by Adam's touch can now only feel disappointed at his return. They reclaim their old life, although that speaks not so much about enduring love as about their mutual desire to present an unbroken façade of their marriage to society.

McEwan stuffs the trim plot with legal technicalities, like citations from famous judgments, allusions to literature and references to music, so much so that the narrative gets dragged down by their weight in places. There are also pontificating and strictly unnecessary statements like "Judges had stood in for the monarch and had been for centuries the guardians of the nation's children." The music comes in such thick layers that all those strains of Bach, Mahler, Schubert, Debussy threaten to turn into a cacophony. But McEwan's readers must have got used to these tricks by now, and his admirers can even fondly overlook them as his habit, not deserving of any special attention. In spite of the self-indulgence that all this excess amounts to, The Children Act can offer a few salubrious hours of entertainment, even of insight. This novel about a judge refrains from delivering any judgment, whether on the conflicted characters or on the question of faith. However, this is not done in a warm-hearted acknowledgment of human imperfection, which brings the arbitrator and the accused together - as it is so often in Shakespeare, another author much obsessed with justice, whom McEwan quotes with regularity - but with a dispassion of the sort that imperils Fiona.