'Excellent,' said Magnus. He put the car into gear and turned left, towards Reykjavik. That was by far the most likely direction and he wanted to catch her up. 'Where are your friends?'

'Tossers,' muttered Jubb as he fiddled with the computer.

Magnus wasn't exactly sure what a tosser was, but he was prepared to take Jubb's word for it. 'Thanks for coming to get me.'

'I should have said something back there,' Jubb said. 'Should have told you everything back when you arrested me.' He clicked a couple of keys. 'Come on ...' he muttered.

'So you bugged her car?'

Jubb just grunted and carried on tapping at the keyboard. 'Here we are. She's north of here. Way north of here. Turn around.'

'Are you sure?'

'Course I'm bloody sure. Take a look.'

Magnus slowed and peered at the computer screen on Jubb's lap. It displayed a map of south-west Iceland, and it showed a round circle moving north along a road on the other side of Fludir.

'Where the hell is she going?' Magnus asked. 'There's nothing up there, is there? Take a look at the map. There's one in the glove compartment.'

Jubb pulled out a map. 'You're right, there's not much north of here. A couple of glaciers, I think they are. The road goes right the way across the middle of the country.'

'It'll still be closed this time of year,' Magnus said.

'Wait a minute. There's something here. Gullfoss? Do you know what that is?'

'It's a waterfall,' said Magnus. 'A massive waterfall.'

Petur pulled into the large car park. This early in the season, and in this weather, it was empty, apart from one tour bus.

He climbed out of his BMW. The enormous waterfall roared at him, unseen, from beyond the far side of the information centre. Tourists emerged along the pathway leading to the waterfall, cooing to each other about the majesty of what they had just witnessed. In five minutes they would be whisked away to the next stop on their tour, the geysers at Geysir, perhaps, or the Althing assembly grounds at Thingvellir.

Good, thought Petur.

Rather than heading straight down towards the waterfall, Petur turned left, upstream. There was now a maintained path leading up the low hill; in his childhood it had just been a narrow sheep track.

Just over the crest of the hill was a shallow hollow. It was here that Dr asgrimur had liked to take his family for a picnic on sunny days. Tourists usually walked to the foot of the falls, or halfway up, or followed the gorge downstream. The hollow, above the falls, offered some privacy, even in the height of summer. The grass and moss, soft and springy, made a comfortable spot to sit, when things were dry.

At the beginning of May, in the mist, things were very wet and there was no sign of anyone. It was only a couple of hundred metres to the car park, but there was no chance of being seen or heard above the din from there.

Petur walked towards the river. The dull roar turned into a crescendo as the magnificent waterfall opened out beneath him. Its power was extraordinary. The Hvita flung itself down into the gorge in two stages, at each throwing up a thick curtain of spray. The resultant tumult was known as Gullfoss, which means 'golden waterfall', because of the tricks of light that low sunshine could play on the fine moisture suspended above the cauldron. In the right conditions rainbows danced gold and purple over the falls.

On a clear day it was possible to see Langjokull, the 'Long Glacier' which produced all this water, crouching between the mountain peaks thirty kilometres to the north. But not today. Today, everything was covered in a grey shroud of moisture, spray and cloud merging into one.

Again, good.

Petur stood and waited for Ingileif.

He was pleased with his choice of meeting place. Like the road to Stong. Petur had tempted Hakon out to that remote spot with a far-fetched tale of how he knew where the helm of Fafnir was hidden. He remembered the look of excitement and expectation on the pastor's face as he had approached him parked above the Fossa. Petur had led the pastor down to the river, and then paused to let him pass. A blow on the back of the head with a rock, and the pastor had tumbled: it was all that Petur had been able to do to stop him from falling straight into the water. He held him back just long enough to ease the ring off his finger, and then tipped him into the torrent. It could be weeks before his body was found, if ever.

That was another effect of the ring on people. It persuaded them to suspend their normal critical faculties, to believe the unbelievable. Petur smiled. The irony that the pastor had fallen for the same ruse that had done for Gaukur a thousand years before pleased him.

Petur stood, staring at the waterfall, and thought of his father. This place really did remind him of that sunny period before things had gone so wrong. Perhaps what he had said to Inga was true. Perhaps their father really was present.

Petur shuddered. He hoped not. He wouldn't want his father to witness what might happen to Inga if she didn't promise to keep quiet.

Petur wondered what the police would think when they found the pastor's body, or more likely his car. An accident? Suicide perhaps?

That was an idea. If the worst came to the worst, and Inga ended up in the waterfall, Petur could claim she had killed herself. He had received a call from her. She was distraught, upset by feelings of betrayal at trying to sell Gaukur's Saga. She told him that she was going to Gullfoss. He feared suicide, and drove up to try to stop her. But he was just too late. He saw her jump.

That would explain his own presence at the waterfall. It would be close enough to the truth that he could carry it off.

He fiddled with the ring on his finger. They would almost certainly arrest him, and it would be hard to describe how he came to have the ring in his possession. Much better to hide it somewhere before he raised the alarm.

But he was getting ahead of himself. As long as he managed to explain things properly to Inga, she would understand him, she would realize he had had no other choice.

Wouldn't she?

Magnus and Steve Jubb sped through Fludir and into the farm-land beyond, dotted with domed greenhouses and emitting spirals of volcanic steam. The road soon ran alongside the Hvita, in full spate.

'I've been a daft bugger,' Jubb said. 'Somehow I thought that Agnar croaking had nothing to do with me. I knew I was innocent but I hoped I could keep the existence of the saga and the ring secret. Seemed worth it then.'

'I thought you had killed the professor,' said Magnus.

'I know you thought that. But I also knew I hadn't. And I guessed you'd figure that out in the end.'

'Have you had any dealings with Petur at all?'

'Never,' Jubb said. 'I hadn't met the bloke till the other day when I saw him with Lawrence Feldman. That man is weird, by the way. Clever. Rich. But weird.'

'And you're not?' said Magnus.

'There's nothing wrong in being a Lord of the Rings fan,' Jubb said defensively. 'What is wrong is when you let it blind you to what's going on in the real world.' He looked around at the extraordinary countryside flashing through the mist around them. 'Although sometimes I find it hard to believe that this country is part of the real world.'

'I know what you mean.'

Magnus's phone rang. Vigdis.

'I can't find Petur at his house or at Neon. They haven't seen him there all day they don't know where he is. I'm just going to check the other two clubs.'

'Don't bother,' said Magnus. 'He's heading to Gullfoss. He's going to meet his sister there. And then he's going to kill her.'

'Are you sure?'

Magnus hesitated. How sure was he? He had made mistakes earlier in this investigation. 'Yeah, I'm sure. Can you call in a SWAT team? What do you call it the Viking Squad. The cloud's probably too low for a helicopter, but the sooner they get here the better.'

'We'll never get the Viking Squad approved,' said Vigdis. 'I will call Baldur. But you and I both know what he's going to say.'

'Damn it!' Magnus knew Baldur would ignore his request. 'Can you come yourself, Vigdis?'

A pause. 'All right. I'm on my way.'

'And bring a weapon.'

'I'll be there as quick as I can. Unarmed.' She hung up.

'Careful!' Steve Jubb flinched as he shouted the warning.

Magnus nearly swerved off the road as he took a bend too fast with only one hand on the wheel. As they were moving north, the road was already deteriorating. Stones slammed against the floor of the car like so many bullets.

'She's stopped at Gullfoss!' Jubb said, staring at his screen.

After careering over some foothills, they descended to cross a narrow gorge at a small suspension bridge and then found themselves on a better road speeding across flat moorland into the fog.

CHAPTER THIRTY-SIX.

PeTUR SAW THE familiar figure of his sister emerge from the gloom over the lip of the hollow. She walked in the same way she had when she was a girl her coat was even the same colour. It brought back memories of those family picnics, before everything had been ruined. At twelve Inga had been really quite pretty, even when wearing her earnest glasses, but she had always been overshadowed by the stunning Birna. Petur felt a sudden surge of affection for his little sister.

She wouldn't let him down. She couldn't possibly let him down.

He raised a hand to greet her.

'Why the hell are we meeting here?' she said, shivering.

'It's the right place,' said Petur gravely. 'It's the right place to talk about Dad.' This wasn't starting well.

'What I want to know is what you were doing driving up to Stong yesterday. They found Hakon's car, you know. And his body at the bottom of Hjalparfoss.'

'I'll tell you about that. But I want to tell you about Dad first.'

'My God!' said Ingileif. 'You know how he died, don't you?'

Petur nodded, meeting her eyes. They were anxious, questioning, but also angry.

'I was with them that weekend. With the pastor and Dad.'

'I thought you were at school.'

'I know. Dad wanted me to come with him on the expedition. He was convinced they would find the ring. I was in two minds about it. As I told you, I was dead against them taking the ring I remembered Grandpa's warnings. But in the end, he persuaded me.

'The trouble was, Mum had forbidden it. So we didn't tell her. I took the bus to Hella from Reykjavik and they picked me up there.'

'So Mum never knew?'

'No.' Petur shook his head. 'We camped out on the hills and then the next morning we got to the cave. It wasn't really a cave, more of a hole in the lava. It took us three hours to find it, but it was Dad who discovered it. He was so excited!'

Petur smiled at the memory. 'And who can blame him? It was amazing. There was this ring, covered in a small film of dust. It's not that it was shining or anything, you had to rub it to tell it was gold. But there was the proof that Gaukur's Saga, this story that had been passed down by all of our ancestors for all those years, was actually true.'

'But you and Dad always thought it was true, didn't you?'

'We believed,' said Petur. 'We had faith. But anyone who has to believe or have faith rather than simply knowing, always has doubts. And to have those doubts dispelled ... Amazing.

'So I was caught up in the whole thing. But after a few minutes I told Dad we had to put it back. I talked about all the evil it would bring the world, how Grandpa had told me to make sure that Dad never took it. We had a major row. Dad looked to Reverend Hakon for support and he got it. I even tried to grab the ring off him, but he pushed me to one side.

'I had kind of ruined everything,' Petur said. 'They walked on together and I followed twenty metres behind, sulking, you could say. Then the weather got bad. It was sunny one moment, the next it was snowing.

'I saw my chance. Dad was in front, the pastor next and then me. I slipped past the pastor and tried to grab the ring from Dad: I knew which of his coat pockets it was in. My plan was to run off into the snow and replace it in the cave. I was pretty sure I could outrun them in the snowstorm and they would soon give up.

'So Dad and I rolled around in the snow, then I pushed him and he fell, hitting his head on a rock.' Petur gulped. The tears came into his eyes. 'I thought I had knocked him out, but he was dead. Just like that.'

'Oh, don't give me that! You pushed him over a cliff! He was found at the bottom of the cliff.'

'I didn't, I swear it. It was only a fall of a couple of metres. It was just the way he hit his head. On his temple right here.' Petur tapped his own shaved skull.

'So how do you explain the cliff?'

'Reverend Hakon saw what had happened. He took charge. I was a wreck after I saw what I had done. My mind was a blank. I couldn't say anything, I couldn't think anything. Hakon knew it was an accident. He told me to go, run away, pretend I was never there. So I ran.

'He pushed Dad over the cliff. Oh, he was dead then, that's for sure, the autopsy people got that wrong when they said he was alive for a few minutes. But Hakon covered for me.'

Ingileif put a hand to her mouth, her brow knitted in anguish. 'I can't believe it,' she said. 'So you were the elf the old sheep farmer saw?'

'Elf?' Petur frowned.

'Never mind.'

Petur smiled at his sister. 'It's true. I killed Dad. But it was a mistake. A dreadful, horrible mistake. If Hakon were alive he could tell you that.' He took a step forward. Took his sister's hands in his. Looked in her eyes horrified, shocked, confused. 'Can you forgive me, Inga?'

Ingileif stood stunned for a moment. Then she backed off.

'It wasn't murder, Inga. Surely you understand that?'

'But what about Aggi? And the pastor? Did you kill them as well?'

'Don't you see, I had to?'

'What do you mean, you had to?'

'As you know by now, Hakon took the ring. When Agnar went to see him, he guessed he had it. He accused Hakon of killing Dad and taking the ring. Hakon threw him out, of course, but then Agnar approached Tomas, tried to get him to act as an intermediary. He tried to blackmail Hakon through him.'

'But what did all this have to do with you?'