“Is this cupboard kept locked?” Erlendur asked.

“No, that is, not during lessons. But apart from that, yes, these cupboards are kept locked.”

“And all the pupils have access to them?”

“Yes, in reality. We haven’t regarded woodwork knives as potential murder weapons until now.”

“But people steal them?” Sigurdur Oli said.

“That’s nothing new,” Egill said, stroking his beard. “Things go missing. Chisels. Screwdrivers. Even saws. Always something every year.”

“Wouldn’t it be a good idea to lock the cupboards then?” Erlendur said. “Hand out the tools under some sort of supervision?”

Egill glared at him.

“Is that any of your business?” he asked.

“They’re knives,” Erlendur said. “Carving knives, what’s more.”

“The classroom is kept locked, isn’t it?” Sigurdur Oli said hurriedly.

“Wood-carving knives are only a weapon in the hands of morons,” Egill said, ignoring Sigurdur Oli. “Why should the rest of us always have to suffer because of a few morons?”

“What about-‘ Sigurdur Oli began, but got no further.

“In addition to which,” Egill persisted, “the kids use these tools in here and can stab themselves or slip them into their schoolbags whenever they like. It’s difficult to keep them under constant supervision.”

“And presumably all the kids in the school will have attended woodwork lessons since you last counted the knives,” Erlendur pointed out.

“Yes,” Egill said, his face flushing an angry red. “The workshop is locked between classes. I don’t leave until the last kid has gone, for safety reasons. I always lock up after myself and I’m the one who opens the door when I arrive in the morning and after all the breaks. No one else. Ever.”

“What about the cleaners?” Sigurdur Oli asked.

“Oh, and them, of course,” Egill said. “But I haven’t been aware that any of the cupboards have been broken into.”

“So in your view the most likely scenario is that the knife was taken during a lesson?” Sigurdur Oli said.

“Don’t start blaming me for that!” Egill almost shouted, beside himself with indignation. “I can’t possibly be expected to keep an eye on everything that goes on here! If some stupid kids want to steal from the workshop it wouldn’t exactly be difficult. And, yes, I reckon it must have been during a lesson. I can’t see how else it could have happened.”

Erlendur picked up one of the knives and tried to recall what the pathologist had said about the instrument used to stab Elias. A broad but not very long blade, he remembered. The carving knife had a very sharp point, a short blade and a broad reverse by the wooden handle. It was razor sharp. Erlendur imagined that it would not require much force to push it deep into someone’s flesh. It struck him that it would also be possible to produce satisfying scratches on cars with a tool like a carving knife.

“How many kids do you think we’re talking about?” he asked. “If we assume that the knife was stolen during a lesson?”

Egill considered.

“Most of the kids in the school, I expect,” he said.

“We’ll have to get a photo of one of these knives and circulate it,” Erlendur said.

“Is this the boy you were asking me about in the car?” Egill asked Erlendur, his eyes fixed on Sigurdur Oli.

A faint smile twisted Erlendur’s lips. He had riled the woodwork teacher and now Egill was after revenge.

“We should get moving,” Erlendur said to Sigurdur Oli.

“Has he told you what happened here in “seventy-nine?” Egill continued. “About the riot?”

They had reached the door. Sigurdur Oli opened it and stepped out into the corridor.

“Thanks for your help,” Erlendur said, half turning back to Egill. “This knife business could be very important. You never know what may come out of it”

Erlendur looked at Sigurdur Oli, who didn’t seem to know what was happening, then closed the door in Egill’s face.

“The old bugger,” he said as they walked down the corridor. “What’s this riot he was referring to?”

“It was nothing,” Sigurdur Oli said.

“What happened?”

“Nothing, it was just a stupid prank.”

They had emerged into the open air and were heading towards the car.

“I find it hard to imagine you involved in a stupid prank,” Erlendur said. “You weren’t at this school very long. Did you get into some sort of trouble?”

Sigurdur Oli sighed heavily. He opened the car door and got behind the wheel. Erlendur took the passenger seat.

“Me and three others,” Sigurdur Oli said. “We refused to go outside during the break. It was all very innocent. The weather was terrible and we said we weren’t going outside.”

“Bloody silly of you,” Erlendur said.

“We chose the wrong teacher,” Sigurdur Oli continued in a serious tone. “He was a temporary supply teacher and we didn’t know him but he managed to get on our nerves. That was probably how it started. Some of the boys had tried to disrupt his lessons by taking the piss out of him and so on. Things got out of hand. He started hurling abuse at us and we answered him back insolently. He got angrier and angrier, and starting trying to drag us outside but we fought back. Then some other teachers and pupils joined in and it ended up in a massive brawl throughout the building. People were injured. It was like everyone was venting their rage at once, pupils on teachers and teachers on pupils. When all attempts to calm the situation failed, someone called the police. It ended up in the papers.”

“And it was all your fault,” Erlendur said.

“I was involved and got suspended for two weeks,” Sigurdur Oli said. “All four of us were suspended, along with some others who’d got a bit carried away in the fight. My father went ballistic”

Erlendur had never heard Sigurdur Oli talk about his father before, never heard him so much as mention his name, and wondered if he should take the opportunity to find out more. The whole thing was completely novel to him. He couldn’t imagine Sigurdur Oli being suspended from school.

“It… I…” Sigurdur Oli wanted to say more but floundered in his attempt to find the words. “It wasn’t like me at all. I’d never been mixed up in anything like that before and I’ve never lost control of myself since.”

Erlendur said nothing.

“I injured the teacher really badly,” Sigurdur Oli said.

“What happened?”

“That’s why everyone remembers it. He was taken to hospital.”

“Why?”

“He fell and cracked his head on the floor,” Sigurdur Oli said. “I knocked him down and he landed on his head. At first I didn’t think he was going to pull through.”

“You can’t have been very happy with that on your conscience.”

“I … I wasn’t very happy at the time. There were various things that…”

“You don’t have to tell me.”

“They got divorced,” Sigurdur Oli said. “My parents. That summer.”

Ah,” Erlendur said.

“I moved out with my mother. We’d only been here two years.”

“It’s always rough on the kids. When their parents split up.”

“Were you discussing me with that woodwork teacher?” Sigurdur Oli asked.

“No, he recognised you,” Erlendur said. “Remembered the riot”

“Did he mention my dad at all?” Sigurdur Oli said.

“He may have done,” Erlendur said guardedly.

“Dad was always working. I don’t think he ever realised why she left him.”

“Had it been on the cards for a long time?” Erlendur asked, amazed that Sigurdur Oli was willing to discuss this with him.

“I didn’t know the background. Still don’t really know what happened. My mother didn’t much like talking about it.”

“You’re an only child, aren’t you?”

Erlendur recalled that Sigurdur Oli had once alluded to the fact.

“I spent a lot of time alone at home,” Sigurdur Oli said, nodding. “Especially after the divorce, when we moved house. Then we moved again. After that we were always moving.”

Neither of them spoke.