At Belgrave Hall, small girls of great privilege are hothoused by a fine headmistress, Lily Lidbury. The exclusive prep school on which Shirley Eskapa’s deft, dark new novel, In a Naked Place (Quartet, £15) centres, seems safe as high-end houses before the credit crunch.

Such is its cachet that parents put their daughters’ names down almost before the Apgar score is recorded. The yummiest mummies jostle for pride of place on the PTA. But Lily’s consummate professionalism conceals the loneliness of ongoing bereavement.

Educating other people’s children became her solace and satisfaction after losing a husband to divorce and, far, far worse, a daughter to unimaginable tragedy. Enter Savannah, a troubled nine-year-old uncannily like her own dead child, and Lily falls headlong into the trap of favouritism — and the adulterous arms of Savannah’s investment-banker father.

Eskapa has written before — always with incisive intelligence — of the mighty misjudgments adults make, and of love triangles from which no one, husband, wife, mistress or children, escapes unbowed. Here, she lays bare the risk that lust provokes, and the consequent guilt that ultimately and shockingly, recasts their lives.

Eskapa has her finger on the pulse of human pain, as well as a sharp eye for the humdrum details that can blow a house down and a love affair apart.

Without scuppering any surprises, one may reveal that Savannah’s chillingly careerist mother turns out to be not half as indifferent to her husband and daughter as they — or she — envisaged. This may be a schoolroom novel, but its hardest lessons are learned between the sheets by believably fallible characters who, as the proverbial report reproves, “could do better”.