Seamus Heaney, in one of his poems, uses the phrase, ‘When grief turns to grievance.’ His context is the sectarian conflict in Northern Ireland where, until the Good Friday Agreement of 1998, a sense of historical injustice was expressed in acts of violence whose victims were often personally innocent, but judged guilty by virtue of race or religion.

This process — of a hurt that doesn’t heal but settles into anger; and of that anger finding release in hurting someone who has no connection with its source — interested me deeply. It’s a universal feature of human behaviour, one that we all have to struggle against when tragedy strikes, but I was drawn to Northern Ireland because it seemed to me rich in possibilities when considering grievance as the dominant theme of a novel. I’m not Irish myself, but I have close family in Northern Ireland and felt that I knew the people well enough to write about them.

At the heart of Grievance is a family tragedy. Gerald Doyle, a respected figure in a small, largely Catholic town, a proud man who craves admiration but shrinks from the idea of being pitied, is devastated when his son, Felix, is born with Down’s Syndrome. In his case an entirely natural grief fails to heal but turns to grievance.

Having nobody directly to blame, he finds an outlet for his anger within the family, where he neglects his wife and develops an increasingly acrimonious and bullying relationship with his daughter, Nora. At the same time he finds comfort in the historical grievances of his tribe, becoming more bigoted in his views just at the point when his fellow republicans are striving to put the past behind them.

I felt that the Doyles’ story, of bringing up a severely handicapped child, had particular resonance in Catholic Ireland, where there is pressure from the community to regard the birth of such a child as a blessing. But for me that story offered an opportunity unconnected with Ireland.

I have a son with Down’s Syndrome and had long wanted to write a novel that was without sentimentality, but nonetheless showed the full range of emotions — joy, grief, love, anger, remorse — of which such a child is capable. On the other hand, Felix stands alone in Grievance in being incapable of nursing a grievance.

The central character, however, is his sister Nora, who is as clever and gifted as Felix is disadvantaged, and whose relationship with her brother is the emotional core of the book. In a narrative that runs parallel to the Irish story we see her trying to make a new life for herself at university in London. Having come from a place where the past is always present, she hopes to leave behind the misery of her childhood and be reborn into a new self.

I grew very attached to Nora in the course of telling her story, but nonetheless felt it was unrealistic to believe that she would not be damaged by her upbringing. Nora herself says at one point, in a conversation about Irish history, that people are not ennobled by suffering. When one of her professors falls in love with her — a man whom she had hoped might assume part of the role of father — she shows herself to be as capable of grievance, and of cruelty, as her actual father.