'With all due respect for your ability to find your way through complicated criminal investigations, this seems pretty vague to me,' said Hansson. 'Let's suppose that you're right. That Kajsa Stenholm was in fact involved in the investigation into the killing of young Alexandersson. So what? Are you suggesting that a woman dying of cancer murdered a man who showed up out of her past?'

'It is very vague,' Wallander admitted. 'Let's wait and see what Åkeson comes up with.'

When Wallander was alone in his office again, he sat around for some time in a state of indecision. He wondered what Mona and Linda were doing at the moment. And what they were talking about. At about nine thirty he went to get a cup of coffee, and another one an hour or so later. He had just returned to his office when the telephone rang. It was Åkeson.

'It went quicker than I'd expected,' he said. 'Do you have a pen handy?'

'I'm all set,' Wallander said.

'Between 10 March and 9 October 1980, Kajsa Stenholm was working as a prosecutor in the city of Stockholm,' Åkeson said. 'With some help from an efficient registry clerk at the county court, I found the answer to your second question, about whether Kajsa Stenholm was involved in the Bengt Alexandersson case.'

He fell silent. Wallander could feel the tension rising.

'It seems you were right,' said Åkeson. 'She was in charge of the preliminary investigation, and she was also the one who eventually put it aside. When the killer wasn't found.'

'Thank you for your help,' said Wallander. 'I'll look into this. I'll be in touch in due course.'

He hung up and walked over to the window. The glass was misted over. It was raining more heavily now. There's only one thing to do, he thought. I must get inside the house and find out what actually happened. He decided to take only Rydberg with him. He called him and Hansson on the intercom, and when they were in his office he told them what Åkeson had found out.

'Well, I'll be damned!' said Hansson.

'I thought you and I should take a drive out there,' Wallander said to Rydberg. 'Three would be one too many.'

Hansson nodded; he understood.

They drove to Svarte in Wallander's car. Neither spoke. Wallander parked about a hundred metres short of Stenholm's property.

'What do you want me to do?' asked Rydberg as they walked through the rain.

'Be there,' Wallander said. 'That's all.'

It suddenly struck Wallander that this was the first time Rydberg had ever assisted him, rather than the other way round. Rydberg had never formally lorded it over his colleague; it didn't suit his temperament to be a boss, and they had always worked in tandem. But during the years Wallander had been in Ystad, it was Rydberg who had been his teacher. Everything he knew today about the work of a police officer was mainly due to Rydberg.

They went through the gate and up to the front door. Wallander rang the bell. As if they had been expected, the door was opened almost immediately by the elderly doctor. Wallander thought in passing that it was odd the Labrador hadn't appeared.

'I hope we're not disturbing you,' Wallander said, 'but we have a few more questions that can't wait, unfortunately.'

'What about?'

Wallander noticed that all the friendliness the man had shown before was gone. He seemed scared and irritated.

'About that man on the beach,' Wallander said.

'I've already told you I've never seen him.'

'We'd also like to talk to your wife.'

'I've told you she's fatally ill. What could she have seen? She's in bed. I don't understand why you can't leave us in peace!'

'Then we won't disturb you any more,' said Wallander. 'Not just now, at least. But I have no doubt we'll be back. And then you'll have to let us in.'

He took Rydberg's arm and steered him towards the gate. The door closed behind them.

'Why did you give in so easily?' Rydberg asked.

'Something you taught me,' Wallander said. 'That it does no harm to let people stew for a while. Besides, I need a warrant from Åkeson to search the house.'

'Is he really the one who killed Alexandersson?' asked Rydberg.

'Yes,' said Wallander. 'I'm certain of it. He's the one. But I still don't understand how it all fits together.'

That afternoon Wallander received the authorisation he needed. He decided to wait until the next morning. But just in case, he persuaded Björk to have a guard placed on the house until then.

When Wallander woke up as dawn was breaking the next morning, 7 May, and opened the curtains, Ystad was covered in fog. Before taking a shower he did something he had forgotten to do the previous night: he looked up Stenholm in the telephone directory. There was no mention of a Martin or Kajsa Stenholm. He phoned directory assistance and ascertained that the number was unlisted. He nodded to himself, as if that was exactly what he had expected.

As he drank his morning cup of coffee, he asked himself if he should take Rydberg with him or drive out to Svarte on his own. It wasn't until he was behind the wheel that he decided to go himself. The fog was thick along the coast road.

Wallander drove very slowly. It was nearly eight when he pulled up outside the Stenholm house. He walked through the gate and rang the doorbell. It wasn't until the third ring that the door opened. When Stenholm saw that it was Wallander, he tried to slam it shut again, but Wallander managed to put his foot in the way.

'What right do you have to break in here?' the old man shouted in a shrill voice.

'I'm not breaking in,' Wallander said. 'I have a search warrant. You might as well accept that. Can we sit down somewhere?'

Stenholm suddenly seemed resigned. Wallander followed him into a room full of books. Wallander sat down in a leather armchair, and Stenholm sat opposite him.

'Do you really have nothing to say to me?' Wallander asked.

'I haven't seen anybody wandering up and down the beach. Nor has my wife, who's seriously ill. She's in bed upstairs.'

Wallander decided to come right to the point. There was no reason to beat around the bush any longer.

'Your wife was a public prosecutor,' he said. 'For most of 1980 she was assigned to Stockholm. Among a lot of other things, she was in charge of a preliminary investigation into the circumstances surrounding the death of an eighteen-year-old named Bengt Alexandersson. She was also responsible for putting the case aside some months later. Do you recall those events?'

'Of course not,' said Stenholm. 'It has always been our habit not to talk shop at home. She said nothing about the people she was prosecuting, I said nothing about my patients.'

'The man who was walking on the beach here was the father of Bengt Alexandersson,' said Wallander. 'He was poisoned and died in the back seat of a taxi. Does that seem like a mere coincidence?'

Stenholm made no reply. And then the penny suddenly dropped for Wallander.

'When you retired you moved down from Nynäshamn to Skåne,' he said slowly. 'To a place in the middle of nowhere like Svarte. You're not even in the telephone book because your number's unlisted. Needless to say, that could be because you want to be left in peace and quiet, to live out your old age in anonymity. But there could be another explan ation. You might have moved out here as discreetly as possible in order to escape from something or somebody. Perhaps to get away from a man who can't understand why a prosecutor didn't put more effort into solving the pointless murder of his only child. You moved, but he tracked you down. I don't suppose we'll ever know how he managed that. But one day, there he is on the beach. You meet him while you're out walking your dog. Naturally, it's a big shock. He repeats his accusations, maybe he even makes threats. Your wife is seriously ill upstairs. I have no doubt that's the case. The man on the beach keeps on coming back, day after day. He won't let you shake him off. You see no way of getting rid of him. No way out at all. Then you invite him into your house. Presumably you promise him that he can talk to your wife. You give him some poison, possibly in a cup of coffee. Then you suddenly change your mind and tell him to come back the next day. Your wife is in great pain, or perhaps she's asleep. But you know he'll never come back. The problem is solved. Göran Alexandersson will die of something that looks like a heart attack. Nobody has ever seen you together, nobody knows about the link between you. Is that what happened?'