“It’s weird coming back here after all this time,” Sigurdur Oli said.

“Small world, this town.”

“What did he say about Dad?”

“Nothing.”

“Dad was a plumber. He was known as Permaflush.”

“Really?” Erlendur said, feigning ignorance.

“Egill remembered me clearly. I could tell at once. I remember him too. We were all a bit scared of him.”

“Well, he’s not exactly Mr Nice Guy,” Erlendur said.

“I know people used to call Dad that, he was the type. You could make fun of him. Some people are like that. He didn’t mind but I couldn’t stand it.”

Sigurdur Oli looked at Erlendur.

“I’ve tried to be everything he wasn’t.”

She greeted Erlendur at the door with a smile, a small woman in her sixties with thick, brown, shoulder-length hair and friendly eyes that radiated complete ignorance about the purpose of his visit. Erlendur was alone. He had popped over at lunchtime on the off-chance that he would find her at home. The woman lived in Kopavogur and was called Emma, that was all he knew.

He introduced himself and when she heard that he was a detective she invited him into an overheated sitting room. He hastily removed his coat and unbuttoned his jacket. It was minus nine outside. They sat down. Everywhere there were signs that she lived alone. She had an aura of extraordinary calm, a serenity that suggested a solitary existence.

“Have you always lived alone?” he asked to break the ice and help her relax, only realising too late what a personal question it was. She seemed to think so too.

“Is that something the police need to know?” she asked, her manner so deadpan that he wasn’t sure if she was teasing him.

“No,” Erlendur said sheepishly. “Of course not.”

“What do the police want with me?” the woman asked.

“We’re looking for a man,” he said. “He was once a neighbour of yours. You lived in the flat opposite him. It’s rather a long time ago, so I don’t know if you’ll remember him, but I thought it was worth a try.”

“Does it have something to do with that terrible case in the news, with that boy?”

“No,” Erlendur said, telling himself that this was not strictly a lie. He didn’t know exactly what he was looking for or why he was intruding on this woman.

“It’s dreadful knowing that something like that can happen,” the woman said. “That a child should be attacked like that, it’s quite incomprehensible, an incomprehensible outrage.”

“Yes, it is,” Erlendur said.

“I’ve only lived in three places in my life,” the woman added. “The place where I was born, the block of flats you’re talking about and here in Kopavogur. That’s it. What year was this?”

“I’m not absolutely certain, but we’re probably talking about the end of the sixties or beginning of the seventies. It was a small family. A mother and son. She may possibly have been living with a man at the time she was resident in the block. It’s him I’m looking for. He wasn’t the boy’s father.”

“Why are you looking for him?”

“It’s a police matter,” Erlendur said and smiled. “Nothing serious. We just need to have a word with him. The woman’s name was Sigurveig. The boy was called Andres.”

Emma hesitated.

“What?” Erlendur said.

“I remember them well,” she said slowly. “I remember that man. And the boy. The mother, Sigurveig, was an alcoholic. I used to see her coming home late at night, drunk. I don’t think she looked after the boy properly. I don’t think he was very happy.”

“What can you tell me about the man she lived with?”

“His name was Rognvaldur. I don’t know his patronymic, I never heard it. He was at sea, wasn’t he? Anyway, he wasn’t home much. I don’t think he drank, at least not like her. I didn’t really understand what they saw in each other, they were such different types.”

“Do you mean they didn’t seem fond of each other or … ?”

“I never understood that relationship. I used to hear them quarrelling, I could hear it through their door if I was on the landing—”

She abruptly broke off her account as if she felt it necessary to clarify.

“I wasn’t eavesdropping,” she said, with a faint smile. “They used to argue pretty loudly. The laundry was in the basement and I’d be on my way down there or coming home …”

“I see,” Erlendur said, picturing her standing on the landing with ears pricked outside her neighbours” door.

“He spoke to her as if she was worthless. Always denigrating her, mocking and humiliating her. I didn’t like him, from what little I had to do with him, not that that was much. But I heard what he was like. Nasty. A nasty piece of work.”

“What about the boy?” Erlendur asked.

“Quiet as a mouse, poor little thing. He avoided the man completely. I had the impression he wasn’t happy. I don’t know what it was, he was somehow so forlorn. Oh, those poor little dears, some of them are just so vulnerable …”

“Can you describe this Rognvaldur for me?” Erlendur asked when she trailed off in mid-sentence.

“I can do better than that,” Emma said. “I believe I have a photo of him somewhere.”

“You do?”

“Where he’s walking past the block of flats. My friend took a picture of me standing outside the front door and it turned out that he was in the background.”

She stood up and went over to a cabinet. Inside were a number of photograph albums, one of which she removed. Erlendur looked around the flat. Everything was spotlessly tidy. He guessed that she put her photos in an album the moment she had them developed. Probably numbered them and labelled them with the date and a short caption. What else was one to do alone in a flat like this during the long, dark winter evenings?

“One of his forefingers was missing,” Emma said as she brought the album over. “I noticed it once. He must have had an accident”

“I see,” Erlendur said.

“Maybe he was doing some carpentry. It was only a stump. On his left hand.”

Emma sat down with the album and turned the pages until she found the picture. Erlendur was right, the photos were carefully arranged in chronological order and clearly labelled. He suspected that every single one had a place in her memory.

“I simply adore looking through these albums,” Emma said, inadvertently confirming Erlendur’s guess.

“They can be precious,” he said. “Memories.”

“Here it is,” she said. “It’s actually not a bad picture of him.”

She handed Erlendur the album and pointed to the photo. There was Emma, more than thirty years younger, smiling at the camera, a slender figure wearing a headscarf, a pretty little cardigan and Capri pants. The picture was in black and white. Behind her he saw the man she referred to as Rognvaldur. He was also looking at the camera but had raised a hand as if to shield his face, as if it had dawned on him too late that he might be caught in the shot. He was thin with a receding hairline, fairly large protruding eyes and delicate eyebrows below a high, intelligent forehead.

Erlendur stared at the man’s face and a shiver ran down his spine when he realised that he had seen him before, very recently. He had changed extraordinarily little despite the passage of time.

“What’s the matter?” Emma asked.

“It’s him!” Erlendur groaned.

“Him?” Emma said. “Who?”

“That man! Is it possible? What did you say his name was?”

“Rognvaldur.”

“No, his name’s not Rognvaldur.”

“Oh, then I must be mistaken. Do you know him?”

Erlendur looked up from the album.

“Is it possible?” he whispered.

He looked again at the man in the picture. He didn’t know anything about him but he had been inside his home and knew who he was.

“Did he call himself Rognvaldur?”

“Yes, that was his name,” Emma said. “I don’t think I’m making it up.”

“I don’t believe it,” Erlendur said.

“Why? What’s the matter?”

“He wasn’t called Rognvaldur when I met him,” Erlendur said.