Souls are such fragile things that even the best and best-hearted judges can drop

Believers of a millennial bent might consider this a sign: It’s not every summer that we get two dark and serious novels focused on Jehovah’s Witnesses.

The first was Scott Cheshire’s “High as the Horses’ Bridles,” about a boy preacher who drifts from the faith. And now the second coming: Ian McEwan’s “The Children Act,” which puts the church’s beliefs on trial.

Surely members of this small Christian sect would prefer instead to get their own hilarious Broadway musical, but authors work in mysterious ways.

The two novels have little in common, except that in both a faithless protagonist is deeply shaken by the behavior of a devout Witness.

McEwan, who has spent more time on the Booker shortlist than in church, has produced a svelte novel as crisp and spotless as a priest’s collar.

“The Children Act” is too long to call a novella, but it has that focused intensity and single arc. At the dramatic center of the story is Fiona Maye, a mature and well-respected British High Court judge in the Family Division. Fiona has devoted much of her career to adjudicating bloody conflicts between once-devoted husbands and wives.

Every day she observes: “Loving promises were denied or rewritten, once easy companions became artful combatants crouching behind counsel, oblivious to the costs.”

In her weary astonishment at these savage ex-lovers, one can sense the expertise McEwan gained when his own divorce and custody fight spilled out into the public arena some 15 years ago.

But if abusive spouses absorb the bulk of Fiona’s court time, she has also ruled famously in more wrenching matters. With efficiency and elegance so alien to legal writing, McEwan draws us through her reasoning on several cases, such as one involving conjoined twins, whose devout Catholic parents refused to give permission for them to be separated, though doing so was the only way to save one of them.

Fiona appreciates that these crises are always wrenching, always murky, which gets us to this central case. A hospital requests an emergency hearing for permission to treat a young leukemia patient who refuses to accept a transfusion that could save his life. Adam Henry and his parents are Jehovah’s Witnesses who believe that the Bible expressly forbids “mixing your own blood with the blood of an animal or another human being.”

McEwan designs the facts to make Adam’s case as morally and legally vexed as possible: Just three months shy of his 18th birthday, Adam can already see that promised land in which his right to determine his own health care would be inviolate.

McEwan may be an atheist, but unlike his late friend Christopher Hitchens he’s a great novelist, not a great polemicist, and he knows that there can be no tension — no art — if Adam and his parents are reduced to ignorant Bible-thumpers clad in what Hitchens called the “heavy coat of ignorance and fear.” Fiona reflects her creator’s fair regard for these Witnesses.

But “The Children Act” is not primarily about religious radicalism or the conflict between faith and science. It’s about the way a woman’s well-ordered life is shaken by a confluence of youthful passion and old betrayal — by her husband who wants to pursue an affair.

In the precisely choreographed pages that follow, McEwan presents a ferociously intelligent and competent woman struggling to rule on a complex legal matter while feeling humiliated and betrayed by her husband.

Beneath her formidable wisdom and accomplishments swirl all the old anxieties of loneliness and shame. Fiona knows that “to be the object of general pity was also a form of social death. The nineteenth century was closer than most women thought.”

She has spent decades training her mind to discriminate between relevant and irrelevant facts, to identify patches of fogginess and sentimentality in her thinking. But this crisis at home threatens to disrupt her carefully managed equilibrium. In that disrupted state, she’s moved by Adam’s irrepressible spirit, and she raises expectations that could either save or doom them both.

And who could blame her? In Adam, McEwan has created a captivating creature with the confidence and eerie mirth of a brilliant young man hovering at the precipice. Distilled by illness, he has only his concentrated naivete left. Even as he struggles to breathe, he’s intoxicated by the fawning attention, the promise of glory, the romantic tragedy of his wasted, blue-veined body.

Can this famously careful woman be careful enough with his fragile soul to understand the true demands of his welfare?

In the end, McEwan arrives at the same conclusion Hitchens left behind, but there’s no stridency in these pages, which glide from one quietly perfect sentence to another.

“The Children Act” doesn’t enact the happy triumph of humanism. Instead, it recognizes how fragile we all are and how cautious we should be about disrupting another’s well-ordered universe.

This story was originally published September 26, 2014 at 7:00 AM with the headline "Souls are such fragile things that even the best and best-hearted judges can drop."