They were able to guess his age, but had more trouble determining which part of the world he came from.

They thought he was about ten years old. He was wearing a grey anorak, unzipped, with a hood, and military-style camouflage trousers. His school bag was on his back. One of his boots had come off and there was a hole in his sock. One toe poked through. The boy was not wearing gloves or a hat. His black hair was already frozen to the ice. He lay on his stomach with one cheek turned up towards them, and they saw his broken eyes staring along the frozen earth. The puddle of blood underneath him had started to freeze.

Elinborg knelt down beside the body.

“Oh my God,” she groaned. “What on earth is happening?”

She held out her hand, as though she wanted to touch the body. The boy looked as if he had lain down to take a rest. She had difficulty controlling herself, did not want to believe what she saw.

“Don’t move him,” Erlendur said calmly. He was standing by the body with Sigurdur Oli.

“He must have been cold,” Elinborg muttered, withdrawing her hand and slowly getting to her feet.

It was the middle of January. The winter had been reasonable until the New Year, when the temperature dropped sharply. The ground was now covered in a solid coating of ice and the north wind howled and sang around the blocks of flats. Rippling sheets of snow swept along the ground. They collected into little drifts here and there and fine powder snow swirled away from them. Straight from the Arctic, the wind bit their faces and penetrated their clothes, cutting to the bone. Erlendur thrust his hands deep into the pockets of his winter coat and shuddered. The sky was heavy with cloud and it was dark, although it had only just turned four o’clock.

“Why do they make military trousers like that for children?” he asked.

The three of them stood hunched over the boy’s body. The blue flashing lights of the police cars bounced off the surrounding houses and blocks of flats. A few passers-by had gathered by the cars. The first reporters had arrived. Forensics were photographing the scene, their flashes vying with the blue lights. They sketched the layout of the area where the boy was lying and the immediate surroundings. The forensic investigation was in its initial stages.

“Those trousers are in fashion,” Elinborg said.

“Do you think there’s something wrong with that?” Sigurdur Oli asked. “Kids wearing trousers like those?”

“I don’t know,” Erlendur said. “Yes, I find it odd,” he added after a pause.

He looked up at the block of flats. People were outside on the balconies watching, in spite of the cold. Others stayed indoors and made do with the view through the window. But most were still at work and their windows were dark. The officers would have to go to all the apartments and talk to the residents. The witness who had found the boy said that he lived there. Perhaps he had been alone and had fallen off the balcony, in which case this could be recorded as a nonsensical accident. Erlendur preferred that theory to the idea of the boy having been murdered. He could not pursue that thought through to the end.

He scrutinised the surroundings. The garden behind the flats did not seem well kept. In the middle was a patch of gravel that served as a little playground. There were two swings, one broken so that the seat hung down to ground level and spun around in the wind; a battered slide that had originally been painted red but was now patchy and rusty, and a simple see-saw with two little seats made from bits of wood, one end frozen solid to the ground and the other standing up in the air like the barrel of a large gun.

“We need to find his boot,” Sigurdur Oli said.

They all looked at the sock with the hole in it.

“This can’t be happening,” Elinborg sighed.

Detectives were searching for footprints in the garden but darkness was falling and they couldn’t see much on the frozen ground. The garden was covered with a coat of slippery ice, occasional clusters of grass poking through it. The district medical officer had confirmed the death and was standing where he thought he would be sheltered from the gale, trying to light a cigarette. He was uncertain about the time of death. Somewhere in the past hour, he thought. He had explained that the forensic pathologist would calculate the exact time of death by correlating the degrees of frost with the body temperature. On first impression the doctor could not identify a cause of death. Possibly a fall, he said, looking up at the gloomy block.

The body had not been disturbed. The pathologist was on his way. If possible he preferred to visit the crime scene and examine the surroundings with the police. Erlendur was concerned at the ever-growing crowd gathering at the corner of the block, who could see the body lit up by the flashing cameras. Cars cruised slowly past, their passengers absorbing the scene. A small floodlight was being erected to enable a closer examination of the site. Erlendur told a policeman to cordon off the area.

From the garden, none of the doors appeared to open out onto a balcony from which the boy might have fallen. The windows were all shut. This was a large block of flats by Icelandic standards, six storeys high with four stairwells. It was in a poor state of repair. The iron railings round the balconies were rusty. The paint was faded and in some places it had flaked off the concrete. Two sitting-room windows with a single large crack in each were visible from where Erlendur stood. No one had bothered to replace them.

“Do you suppose it’s racially motivated?” Sigurdur Oli said, looking down at the boy’s body.

“I don’t think we should jump to conclusions,” Erlendur said.

“Could he have been climbing up the wall?” Elinborg asked as she, too, looked up at the apartment block.

“Kids do the unlikeliest things,” Sigurdur Oli remarked.

“We need to establish whether he might have been climbing up between the balconies,” Erlendur said.

“Where do you think he’s from?” Sigurdur Oli wondered.

“He looks Asian to me,” Elinborg said.

“Could be Thai, Filipino, Vietnamese, Korean, Japanese, Chinese,” Sigurdur Oli reeled off.

“Shouldn’t we say he’s an Icelander until we find out otherwise?” Erlendur said.

They stood in silence in the cold, watching the drifting snow pile up around the boy. Erlendur looked at the curious bystanders at the corner where the police cars were parked. Then he took off his coat and draped it over the body.

“Is it safe doing that?” Elinborg asked with a glance in the direction of the forensics team. According to procedure they were not even supposed to stand over the body until forensics had granted permission.

“I don’t know,” Erlendur said.

“Not very professional,” Sigurdur Oli said.

“Has no one reported the boy missing?” Erlendur asked, ignoring his remark. “No enquiries about a lost boy of this age?”

“I checked that on the way here,” Elinborg said. “The police haven’t been notified of any.”

Erlendur glanced down at his coat. He was cold.

“Where’s the person who found him?”

“We’ve got him in one of the stairwells,” Sigurdur Oli said. “He waited for us. Called from his mobile. Every kid carries a mobile phone these days. He said he’d taken a shortcut through the garden on his way home from school and stumbled across the body.”

“I’ll talk to him,” Erlendur said. “You check whether they can find the boy’s tracks through the garden. If he was bleeding he might have left a trail. Maybe he didn’t fall.”