Forensics had erected a large tent over the skeleton. Elinborg stood outside it as she watched Erlendur and Sigurdur Oli hurrying across the dry bed of the lake towards her. It was late in the evening and the media had left. Traffic had increased around the lake after the find was reported, but had died down and the area was quiet again.

“Nice of you to find the time,” Elinborg said as they approached.

“Sigurdur had to stop for a hamburger on the way,” Erlendur grunted. “What’s going on?”

“Come with me,” Elinborg said, opening the tent. “The pathologist is here.”

Erlendur looked down towards the lake in the evening calm and thought about the fissures in its bed. The sun was still up, so it was completely daylight. Staring up at the white puffs of cloud directly above him, he was still pondering how strange it was that there had once been a lake four metres deep where he was standing.

The forensics team had unearthed the skeleton, which could now be seen in its entirety. There was not a single piece of flesh or scrap of clothing left on it. A woman aged about forty knelt beside it, picking at the pelvis with a yellow pencil.

“It’s a male,” she said. “Average height and probably middle-aged, but I need to check that more carefully. I don’t know how long he’s been in the water, perhaps forty or fifty years. Maybe longer. But that’s just a guess. I can be more precise once I get him down to the morgue to study him properly.”

She stood up and greeted them. Erlendur knew her name was Matthildur and that she had recently been recruited as a pathologist. He longed to ask her what drove her to investigate crimes. Why she didn’t just become a doctor like all the others and milk the health service?

“He’s been hit over the head?” Erlendur asked.

“Looks like it,” Matthildur said. “But it’s difficult to establish what kind of instrument was used. All the marks around the hole have gone.”

“We’re talking about wilful murder?” Sigurdur Oli said.

“All murders are wilful,” Matthildur said. “Some are just more stupid than others.”

“There’s no question that it’s murder,” said Elinborg, who had been listening.

She scrambled over the skeleton and pointed down to a large hole that the forensics team had dug. Erlendur went over to her and saw that inside the hole was a bulky black metal box, tied by a rope to the bones. It was still mostly buried in the sand but what appeared to be broken instruments with black dials and black buttons were visible. The box was scratched and dented, it had opened up and there was sand inside.

“What’s that?” Sigurdur Oli asked.

“God knows,” Elinborg said, “but it was used to sink him.”

“Is it some kind of measuring device?” Erlendur said.

“I’ve never seen anything like it,” Elinborg said. “Forensics said it was an old radio transmitter. They went off for something to eat.”

“A transmitter?” Erlendur said. “What kind of transmitter?”

“They didn’t know. They’ve still got to dig it up.”

Erlendur looked at the rope tied around the skeleton and at the black box used to sink the body. He imagined men lugging the corpse out of a car, tying it to the transmitter, rowing out onto the lake with it and throwing the whole lot overboard.

“So he was sunk?” he said.

“He hardly did it himself,” Sigurdur Oli blurted out. “He wouldn’t really go out onto the lake, tie himself to a radio transmitter, pick it up, fall over on his head and still take care to end up in the lake so he’d be sure to disappear. That would be the most ridiculous suicide in history.”

“Do you suppose the transmitter’s heavy?” Erlendur asked, trying to contain his irritation with Sigurdur Oli.

“It looks really heavy to me,” Matthildur said.

“Is there any point in combing the bottom of the lake for a murder weapon?” Elinborg asked. “With a metal detector, if it was a hammer or the like? It might have been thrown in with the body.”

“Forensics will handle that,” Erlendur said, kneeling down by the black box. He rubbed away the sand from it.

“Maybe he was a radio ham,” Sigurdur Oli said.

“Are you coming?” Elinborg asked. “To my book launch?”

“Don’t we have to?” Sigurdur Oli said.

“I’m not going to force you.”

“What’s the book called?” Erlendur asked.

“More Than Just Desserts,” Elinborg said. “It’s a pun. Justice — get it — and desserts, and it’s not just desserts…”

“Very droll,” Erlendur said, casting a look of astonishment at Sigurdur Oli, who was trying to smother his laughter.

Eva Lind sat facing him, wearing a white dressing gown with her legs curled up under her on the seat, twiddling her hair around her index finger, circle after circle as if hypnotised. As a rule in-patients were not allowed to receive guests but the staff knew Erlendur well and made no objection when he asked to see her. They sat in silence for a good while. They were in the in-patients” lounge and there were posters on the walls warning against alcohol and drug abuse.

“You still seeing that old bag?” Eva said, fiddling with her hair.

“Stop calling her an old bag,” Erlendur said. “Valgerdur’s two years younger than me.”

“Right, an old bag. You still seeing her?”

“Yes.”

“And… does she come round to yours, this Valgerdur woman?”

“She has done, once.”

“And then you meet at hotels.”

“Something like that. How are you doing? Sigurdur Oli sends his regards. He says his shoulder’s getting better.”

“I missed. I wanted to hit him over the head.”

“You really can be a bloody idiot sometimes,” Erlendur said.

“Has she left her bloke? She’s still married, isn’t she, that Valgerdur?”

“It’s none of your business.”

“So she’s cheating on him? Which means you’re shagging a married woman. How do you feel about that?”

“We haven’t slept together. Not that it’s any of your business. And cut out that filthy language!”

“Like hell you haven’t slept together!”

“Aren’t you supposed to get medication here? To cure your temper?”

He stood up. She looked up at him.

“I didn’t ask you to put me in here,” she said. “I didn’t ask you to interfere in my life. I want you to leave me alone. Completely alone.”

He walked out of the lounge without saying goodbye.

“Say hello to the old bag from me,” Eva Lind called out after him, twiddling her hair as collected as ever. “Say hello to that fucking old bag,” she added under her breath.

Erlendur parked outside his block of flats and entered the stairwell. When he reached his floor he noticed a lanky young long-haired man loitering by the door, smoking. The upper part of his body was in the shadows and Erlendur could not make out his face. At first he thought it was a criminal who had unfinished business with him. Sometimes they called him when they were drunk and threatened him for encroaching in some way or other upon their miserable lives. The occasional one turned up at his door to argue. He was expecting something like that in the corridor.

The young man stood up straight when he saw Erlendur approach.

“Can I stay with you?” he asked, having trouble deciding what to do with his cigarette butt. Erlendur noticed two dog-ends on the carpet.

“Who are…?”

“Sindri,” the man said, stepping from the shadows. “Your son. Don’t you recognise me?”

“Sindri?” Erlendur said in surprise.

“I’ve moved back into town,” Sindri said. “I thought I’d look you up.”

Sigurdur Oli was in bed beside Bergthora when the telephone rang. He looked at the caller ID. Realising who it was, he decided not to answer. On the sixth ring, Bergthora gave him a nudge.

“Answer it,” she said. “It’ll do him good to talk to you. He thinks you help him.”