I would love to say to you that I started out with that title, but I didn’t. It was called The Redeemer, but I became aware that many other books had the same title and moreover, the character is not a redeemer – he is a killer.

My friend from Bosnia, Zrinka Bralo, was in the siege, and she showed me a photograph of the installation in the square in Sarajevo that marked twenty-five years after the siege came to an end. She told me that visitors and dignitaries from all over the world came, but tears were mostly shed at the sight of the little chairs, the emblematic coffins, so to speak, of infants and children who had lost their lives.

Titles are very important to the writer, they are talismanic.

It has been ten years since your previous novel.

With regard to the ten years, I was changing internally. I wanted to break away from anything I had done before, although I’m not disowning it. The gestation of a novel is very slow, which is not always the case with poetry. Seamus Heaney told me that he once wrote a particular poem in an hour, as mind and body were ready for it. A novel takes years and the principal anxiety, apart from getting the words right, is to maintain the momentum and the vigour.

Let’s turn to your research for the novel. You didn’t go to Sarajevo, but I know you went on some trips that were extremely important, including to The Hague.

Yes, I went often and what most incensed me was the absolute righteousness of the man. I attended the hearings of both Karadžić and Mladić and both men were vituperative in their denial of what they had done. Karadžić was swaggering and assured, whereas Mladić was surly, but in both cases they protested innocence and denial, insisting the wrong had been done to them and their people. I was told that in the evenings they sang songs of the homeland, played table tennis, ate well and preferred red wine.

Where else did you go?

My son, Sasha, commented that there were a lot of women in my book. Due to Zrinka’s good offices, I was allowed to visit her centre under the Westway, where a group met each week and terrible stories of terrible deeds unfolded. They were from all over, both men and women, but the women were more open in describing their ordeals.

In fact there was a young man there, who, with his brother, had been in a concentration camp under the aegis of Karadžić and he told us that he could not remember anything because he did not want to. He had dissociated himself from it. His brother asked him how he came through, apparently unscathed, since he witnessed such barbarous horrors and his answer was that he told himself to think of the blue of rivers and waterfalls in his native land.

But the women told you very different stories?

They were embryo poets and also unflinching in their desperation. They got straight to the nub of the matter. Here they were, transplanted from their own countries and their own hearths, doing menial jobs and yet the essence of home and what home meant had never left them.

How did your visit to the kennels come about? I know it influenced the latter parts of the novel.

My son took me. I’ll never forget the arrival. I could smell pee and shit as I went down the three steps, where there was a little attempt at a garden, a few blooms, birds – eight or nine like an augury on a telegraph wire. The hounds were baying inside. Sasha introduced me to staff and explained that Fidelma, a character in my novel, might work in a kennel, her isolation mirroring the plight of the rejected animals.

On the way back, we stopped at a pub in Brentwood and bought a little cardboard funnel of cockles and periwinkles and I thought, I will have Fidelma do the very same thing, in a small room above the bar.

Do you gather a lot of these details as part of your research?

It all has to soak in so that it’s eventually part of a continuous story. The research for me is concerned with the minutiae. I asked the owner of that pub to let me see a bedroom upstairs and when I was coming back down, I touched some white flowers in a little vase on the landing. I expected them to be artificial and when I realised they were real, I started to cry with emotion.

Some critics have mentioned that moment in the book because of the shock and incongruity of tenderness at an unexpected moment and the yearning for touch.

Who did you meet at The Hague?

Many people on the staff helped me and I was given a good seat in the front row. Next to me was a group of women, sad, grey, defeated, yet indomitable. They had come to stare through the perspex, to curse Karadžić, their tormentor, with all their being. Naturally, they were not allowed to heckle or shout.

On the fifth day I was introduced to them in the lobby and I asked the translator to ask what might constitute a moment of redemption in this awful saga. The answer was as profound as anything I have read in any literature. A bone, or even a fragment of a bone. That would unite them to the sons and fathers buried in mass graves and never to be found.

How did this scene develop?

Slowly. It took about three months to write, during which I read several novels with dark and disturbing themes. I read J. M. Coetzee’s Disgrace, Conrad’s Heart of Darkness and a short story of Hemingway’s, ‘The Killers’.

What mattered was to maintain tension in the narrative, while also depicting the car ride, the different sights that they pass, the three thugs – smelling of sex, vodka and kebabs – taunting her, the quaking Nigerian driver and she herself wondering what violation is to be visited upon her and where, wondering will she ever again see the husband she has betrayed.

Do you think it’s easier for a writer to write about evil, misfortune and deprivation? Is it the duty of the great novelist to go to those places?

I never dreamed when I was in my twenties writing The Country Girls that I’d be writing this kind of book or talking to you in this way. Life teaches us. We cannot ignore or avoid what is happening in the world, it is presented on our screens every single moment. It must by necessity come into the work, because we are all witnesses to what is happening. To write about it is not to ease one’s conscience or exalt one’s status. It is simply to be one of the witnesses along the way.

What are your thoughts when you look back at your career and your earlier work?

Pride at having stayed the course and survived some pretty awful battering from both male and female critics.

It’s curious that you decided to set at least the opening third of The Little Red Chairs in contemporary rural Ireland. The people upon whom Vlad is modelled ended up in Belgrade, so why did you choose Ireland?

I wanted to start with the landscape I know, with the idiom I know, that imagery, be it gate hasp or blue-black lake – a friendly, habitable place for a stranger, in the manner of Gilgamesh who washes the dirt of history from himself and enters that unsuspecting milieu.

You’re now at the beginning of another journey and starting to think about writing something else.

I’m a bundle of anxiety, grasping at themes. I’m like a grasshopper. I will have to go somewhere very lonely and very secluded to find the story inside myself that has a corresponding story in the mayhem of the world.

What do you make of contemporary writing?

In an article for the Guardian, I wrote about how in some contemporary writing there’s an absolute mastery of language but at the expense of true feeling, and that the secret transaction between unknown reader and unknown writer is sabotaged. Your involvement with what you read when you are young is with you forever and it still happens in your adult life that somehow the book was more than life. I want immersion from a novel that I read and I don’t always get it.

A book is a prayer. I think literature is the greatest gift to mankind.

The Little Red Chairs is available to buy in paperback. Edna O’Brien’s classic 1965 novel August is a Wicked Month is now also available in a new edition from Faber.