Brian McGilloway - Borderlands

"When was this taken?" I asked.

"Should be written on the back," Duffy replied. "Around Halloween, before she disappeared. The weather was beautiful for so late in the year and we all went to Bundoran for a day out. We had a great day." The dates certainly fitted with Costello's buying the ring.

"That's a nice ring she's wearing," I said. "Looks expensive."

"It was. Didn't stop it breaking, though. In fact on the way home that night she noticed one of the stones had fallen out. Had to send it back to be fixed."

"Where did she get it?" I asked, trying to make the question sound as casual as possible. Still Duffy viewed me with suspicion.

Finally she decided to answer. "I suppose you know anyway. Mary had a lot of men. Made a bit for herself on the back of it. One of her men bought it for her."

"Do you know who?" Williams asked.

"Someone with money. Someone important. One of the important people."

"What do you mean, 'one of?" I asked.

"There were several," Duffy replied, and smiled coyly, as if to suggest she had gone as far as she could.

"Who were they?" Williams asked, reading my thoughts.

"I don't remember names. Some businessmen, important people. The owner of the Three Rivers Hotel was the biggest of them, though."

"Who was that?" I asked. The Three Rivers was derelict now, and had been for as long as I could recall.

"I don't remember," Duffy said, averting her eyes from my mine. "As for the children, I haven't seen them in twenty-five years."

"Do you know what happened to them?" Williams asked. Duffy looked at her and her face reddened. Her eyes began to moisten and she bit lightly at her lip in a vain attempt to stop the tears.

"I took them," she said, finally, as she wiped carefully at her tears. "I know it was wrong, but I took them to Dublin. Left them in an orphanage in South Circular Road – St Augustine's. I gave them a photograph each of their mother from that same batch you're looking at."

"That was it? You just decided to take them away, for no reason?" I asked incredulously. "What if she'd come back?"

"Someone told me to do it – someone who was very fond of Mary. He gave me money to take them. Gave me a hundred punts to give to them. He told me to do it."

"This man told you to give someone else's children away to an orphanage and you did it?" Williams's voice rose so quickly it cracked and she had to swallow back her last words.

"Yes. He told me she wouldn't be back. Said it would be better for the children if they were kept away from Strabane for a while. I thought they might be in some danger. I couldn't look after two children. I did what he said. It wasn't my fault," she said.

"Who was he, Ms Duffy? We need a name."

"I can't tell you."

"Ms Duffy," I said, as reasonably as possible. "Whoever told you to take those children away probably knows what happened to their mother. In fact, he may have been responsible for what happened to her. Now, please, who told you to take them?"

She looked from Williams to me and back again. Then she looked at her hands, clasped in her lap, and finally back at me, a note of defiance clear in her voice and in her eyes. "Costello, his name was," she said, then preened herself slightly in vindication at her reluctance to speak, as we struggled to make sense of what she had told us.

On the journey home, we tried to examine all the pieces of the case as objectively as possible. Costello had been having an affair with a prostitute with two children. She vanishes and he pays a neighbour to have the children taken to Dublin and left in an orphanage. Twenty-five years later a hood's daughter is killed and her body is dumped wearing the ring Costello had given to the prostitute.

"Costello seems to be fitting the frame more and more," Williams said grimly, though neither of us wanted to consider what would happen if we proved decisively that he was responsible for Knox's disappearance.

"It looks that way," I said resignedly, and decided on one final stalling measure. "The best thing for us to do is to try to locate those children: it's the only solution."

"Are you going to speak to him about this?" Williams asked, as we drove through Porthall, approaching Lifford from the east.

"Not yet," I said, though I knew that eventually I would have to face Costello, as surely as I would have to deal with Frank and the attacks on Anderson's livestock. "What are you doing now?" I asked.

The sky was darkening, although it was only just after four o'clock. The moon hung low in the sky, still little more than a sliver of ice. Three or four stars stood out in the navy sky; a bulkhead of cloud building in the west promised snow by morning. We had already overtaken a number of the local farmers out spreading salt on the minor roads.

"No plans. I'm meeting Jason later for dinner. In fact, he's cooking."

"Fancy doing one last thing for us before you shoot home? Check out who owned the Three Rivers when Knox was about. I'll try this St Augustine's place and see what I can find."

The only St Augustine's in the book was a church, though the priest was able to give me a number for a nun named Sister Perpetua, who had worked in the orphanage until 1995 when it had closed down. Sister Perpetua, or Sister P as she announced herself on the phone, was a northerner and proved to be as voluble as her memory was remarkable.

"I remember the Knox children, Inspector, yes," she said, her Fermanagh accent mixed with just a hint of the shorter Dublin twang. "Sean and Aoibhinn." She pronounced the girl's name Eveen. "A sad case. They arrived with us just after New Year, 1979.1 remember because we took some of the children to see His Holiness in Drogheda that year and the Knox children were among them. From what I recall they arrived with next to nothing. An aunt left them off, I think; gave them fifty punts, which was fairly generous in those days." Though still leaving her with fifty punts profit, I thought, for all her socialist beliefs.

She told me the story of the Knox children. It took many months for them to settle into their new home. Their accents, a mix of English and Northern Irish, stood out vividly against the southern brogue of their peers. The girl was subdued and unwilling to participate in any games. The boy was fiercely protective of her and got into more than one fight with people whom he felt were criticizing her. Finally, in September of that year, they were placed with two foster families, on either side of Dublin. The girl lasted four days, the boy less still. They had both cried inconsolably for the other, and, indeed, the boy had attacked his foster mother when she tried to put an arm round him to comfort him. And so they ended up back together again and became suddenly much more settled and content.

It was agreed by all the staff at St Augustine's that the children were precocious with regard to matters of the body. They frequently used coarse language and sexual slang. The boy had to be reprimanded several times for peeping up girls' skirts and, on one occasion, hiding in the girls' toilets.

The children were placed, unsuccessfully, with a number of foster homes, always returning happily to St Augustine's where, for perhaps the first time in their lives, they experienced some stability. Over the next number of years they drifted in and out of foster homes, running away from them before they had a chance to integrate fully. When Sean turned eighteen he left St Augustine's and rented a flat in Dublin, making money doing odd jobs on building sites. When the girl was seventeen she saw an advertisement for a Garda recruitment drive and entered training for An Garda when she turned eighteen.

"She was a beautiful girl, Inspector," Sister Perpetua said, "but troubled. I think she saw the Garda as a chance to join a new family. They were both awful lonely – apart from each other. So… what have they done"