Resistance, by Owen Sheers

Alone one clear moonlit night in her Olchon valley farm in the Black Mountains, in the Welsh border country, Sarah Lewis sees a man's figure in the door-frame. "Tom?" she asks, thinking it her husband back at last. Then the figure steps forward – not Tom, but Albrecht, a German officer, commander of the patrol occupying the valley.

Sarah's mistake reverberates throughout this novel. For middle-aged Albrecht not only possesses those qualities that young Sarah loved in the missing Tom, but meets the needs of her resourceful, sensitive personality during her separation. For Albrecht, too, scholar as well as Wehrmacht officer, the encounter is significant; his loved Ebbe is dead, and he feels drawn to this Welsh farm-woman, so indefatigable in her care for her animals, and well-read, even though, as a certificate on the kitchen wall testifies, she left school at 14.

It is autumn 1944; the war has turned in Germany's favour after Russia's inability to cope with her attack, and invasion of Britain has become occupation, at first meeting continual opposition, later effected by a collaborative government headed by RA Butler in Harrogate. (London is too damaged and potentially insurgent.) The US, over-stretched in Japan, returns to its earlier refusal to get involved in European conflicts, and abandons Britain to its fate.

Details of this alternative course of the Second World War, though given plausibility, are inevitably factitious, and the interests and strengths of the novel lie elsewhere. Apropos the probabilities, I recommend that readers turn first to the fascinating afterword. This will spoil nothing in the careful yet always intriguing plot, and will make them appreciate its firm roots in reality.

Owen Sheers, who grew up in the Black Mountains he so patently knows and loves, heard from locals the story of how some farmers had been given caches of arms, hidden in underground bunkers in the hills. "Should the order have come, these farmers were to leave their homes and wives and take to the Black Mountains to resist the occupying German army." This is what Sarah Lewis's Tom and all the other men farming the Olchon have done.

Obviously there is an "intelligence" operating behind the scheme, and this again derives from the oral history that Sheers has absorbed. Its representative here, a man with a hat covered in fishing-flies, calling himself "Tommy Atkins", again originated in life, as did his principal spy, and tragic catalyst, young George.

Sarah stands apart from the other women in her valley, as Albrecht stands apart from his men, younger and both hardened and destabilised by hellish war experiences. In this remote corner of the Marches, woman and man perform a pas de deux – meeting, withdrawing, choreographed by temperament and inexorable history.

There are many beauties in the novel's delineations of the land's harsh demands and intimate rewards, and of those human spirits who have derived sustenance from it. Outstanding among these last are Sarah's retrospective cameos of the painter-poet David Jones, over at Capel-y-ffin, whom she knew as a girl of nine. War-wounded Jones would surely have been gratified by the tribute.