Fiction: 'I stood and thought of the lakes and forests going on all the way to Russia, and then straight on without taking breath, because borders don't make any difference to the pattern of water and trees."
This observation, from Helen Dunmore's novel, Burning Bright (1994), indicates two of the author's overriding concerns: the atmosphere and countryside of Finland, and shifting political boundaries, with their implications. That novel was set in the present; House of Orphans, like 2001's The Siege (about the Siege of Leningrad), goes back to the past - a bit further back in this instance, to 1902, when conclaves propagating a revolutionary agenda were meeting clandestinely in freezing rooms in the backstreets of Helsinki and St Petersburg. The aims of dismantling repugnant social structures and, in particular, of resisting the "Russification" of Finland were the driving forces behind these confederations.
The social and political circumstances of the time are important to the ethos of the novel. But House of Orphans, now longlisted for the Orange Prize for Fiction, is, above all, about integrity: recognising it, asserting it and keeping it intact. The erosion of integrity is a social evil. Most strikingly, the pristine quality is embodied in the girl Eeva, brief inmate of the orphanage of the title, which is located in a country town a long way from Helsinki, surrounded by forest as dense as anything in the Brothers Grimm. To this institution Eeva has been brought unwillingly, following the death of her father and the arrest, on a trumped-up charge, of her father's friend and fellow activist who'd given her a home. But before long she is free of the orphanage and working as housekeeper to a doctor whose house stands right in the middle of the forest.
Enter the second centre of interest in the book. Dr Thomas Eklund, recently widowed, the father of a grown-up daughter with a grievance against him, and the object of well-meant but fatuous advice from his female friend, Lotta, commands our attention by virtue of his uprightness and his susceptibility. He stands for the values of tradition and continuity, against which Eeva's scholarly and reformist leanings are posed. The way forward lies with Eeva. "Thomas has got a little agitator in his kitchen," Lotta thinks, in a moment of perceptiveness; but in fact Eeva is no extremist, just as Thomas is no autocrat. She is, however, a city girl, to whom the forest is alien territory; and the narrative is driven, in part, by her need to get back to Helsinki, and to re-establish contact with her childhood friend, Lauri, who has stayed true to an unadulterated ameliorist vision and comradeship of the disaffected.
The third story in this tripartite novel is Lauri's, and it's a story of poverty, scruples, class commitment and betrayal, as the agitators' circle is infiltrated - what else? - by informers and double agents. In the meantime, Eeva, as fiercely protective of her independence as ever Jane Eyre was, and Thomas, secure in his world of inherited assets but with his own areas of vulnerability - these two, almost by accident, undertake an idyllic trek together through the forest towards the city: idyllic against the odds, this journey makes a kind of hiatus in a novel teeming with instances of social injustice, conspiracy and calamity.
It is all recounted dispassionately, with a grave and lyrical apprehension of the aspirations and enormities of the day, the frozen streets, the clumsy, communal boots distributed among the orphans, the planned assassinations for a beneficial purpose. Finely crafted and fastidiously imagined, House of Orphans shows Helen Dunmore at her best: subtle and evocative as ever, and displaying the firmest understanding of the strangeness, as well as the ordinariness, of the past.
• Patricia Craig's biography of Brian Moore came out in paperback in 2004. Her Ulster Anthology will be published by Blackstaff next autumn
• House of Orphans By Helen Dunmore Fig Tree, 330pp. £17.99