The year after the end of the Second World War, Germany lay in ruins.

Carved into occupied territories under the control of the Americans, British and Russians, it was more a jigsaw than a country, yet some things united its people: despair, fear and gnawing hunger.

Brook sets his thoughtful and studiedly non-judgemental post-war novel against the backdrop of Hamburg, a city so devastated by bombs that, in 1946, it is more ash than brick. Colonel Lewis Morgan, the hero of this scrupulously nonpartisan story, is at pains to inform his wife Rachael when she and their son Edmund first set eyes on the place: "Do you know that we dropped more bombs on Hamburg in a weekend than the Germans dropped on London in the entire war?"

Rachael thinks they deserved it. How could she not, given that their elder son was killed by a German plane dropping an unused bomb over Cardiff on his way home. She subscribes wholly to the popular view that "the only good German is a dead German". Under questioning from his curious younger son, even Lewis must admit that some people deserve to be punished for the atrocities the Nazis committed.

Very quickly, however, the reader is aware that this kind-hearted and too idealistic man does not seek the certainties and securities of blame and condemnation, nor does he see the utter misery of the vanquished foe as a lesson they have asked for. Feelingly depicting survivors of the Hamburg fire-bombing, among them children so traumatised they have almost lost their minds, Brook creates a pitiful and nuanced portrait of the pointless violence and cruelty of war, in which distinctions between the good guys and the bad are sometimes disturbingly blurred.

When, for instance, a Nazi-hunting British officer flinches at the smell of a scavenging local, Lewis remarks drily: "That's what a diet of 900 calories a day does for you." The officer devoted to rooting out all who helped persecute the Jews sees no irony in revelling in the starvation of others, many of whom were guilty of nothing more than being German and part of a regime that, as one character reminds Lewis, had trapped them all long before war began.

The idea behind this novel is drawn from Brook's grandfather's post-war posting to Hamburg. As with the author's grandfather, Lewis is offered a requisitioned villa for his family. It is a magnificent house, far too large for his own needs, and when the owner shows him politely and hospitably around, he impulsively suggests the two families share it.

The villa's owner, a cultured architect called Lubert, whose wife died in the bombing and whose daughter Frieda is creepily dysfunctional, is almost too perfect as a symbol of Germany's more civilised citizens, a man whose intelligence and sensitivity – especially to Rachael's charms – are almost as winning as the gentle and too-trusting Lewis himself.

Much of what unfolds in this fraught household could be foreseen from the opening chapters. The pleasures of The Aftermath, however, lie not in predicting the plot but in watching the characters unfurl as, each in their own way, they deal with what war has cost them.

While there is greater depth to his male characters, Brook has, in Rachael, created a sympathetic individual, whose sorrow for her lost child and bitter resentment of an always absent and seemingly less grief-torn husband, are, if not endearing, believable. In her loss of desire, not only for her spouse but for life itself, she could be viewed as a symbol for the psychological wasteland left in any war's wake. When, unexpectedly, her emotions stir once more, it represents a moment of great danger for her marriage. As with the subjugated Germany, apathy is considered safer than action. It takes a man of Lewis's insight to know that starvation and hatred are more dangerous forces than any well-fed revolution. Alas, he is less perceptive about his wife's state of mind.

A story about grief, on a domestic and international scale, The Aftermath is an absorbing, readable tale and a rare corrective to the jingoistic, sentimental or thrillerish tone of so many modern novels of this period. Sometimes a little too fair minded, or arguably even naive – as when Lewis bemoans the bombing of Blohm & Voss on the River Elbe, "we did blow up a fully functioning, world-class shipping yard" he chides – it is also on occasion clumsy and over-written as if Brook does not trust the material and his characters to speak for themselves.

These quibbles aside, The Aftermath is a reflective act of compassionate but tough-minded observation. Offering sufficient detail to create a post-war mood, yet never wallowing in vintage trappings, this is a stylish, heart-searching and convincing story that by refusing to peddle cliches and received wisdom, memorably refashions this period.

The Aftermath

Rhidian Brook, Penguin, £14.99