During the last few years, vigilante groups had been on the rise in Sweden, groups like The Civilian Guard. Wallander had long feared this development. When the justice system started to break down, the lynching mentality of the mob took over. Taking justice into one's own hands came to seem normal.

As he stood there at the window, he wondered how many illegal weapons were floating around Sweden. And he wondered what the figures would be in a couple of years.

He sat down at his desk. His door was slightly ajar and he heard voices out in the corridor, and a woman's laugh. Wallander smiled. That was their chief of police, Lisa Holgersson. She had replaced Björk a few years ago. Many of Wallander's colleagues had resisted the idea of a woman in such a high position, but Wallander gained respect for her early on.

The phone rang. It was Ebba, the receptionist.

"Did it go well?" she asked.

Wallander realised she meant yesterday. "The house isn't sold yet, of course," he said. "But I'm sure it will go well."

"I'm calling to see if you have time to talk to some visitors at 10.30 this morning."

"Visitors at this time of year?"

"It's a group of retired marine officers who meet in Skåne every August. They have some sort of society. I think they call themselves 'The Sea Bears'."

Wallander thought about his doctor's appointment. "I think you'll have to ask someone else this time," he answered. "I'm going to be out between 10.30 and midday."

"Then I'll ask Ann-Britt. These old sea captains might enjoy talking to a woman police officer."

"Or else they'll think just the opposite," Wallander said.

By 8 a.m. Wallander had not managed to do anything more than rock back and forth in his chair and look out the window. Tiredness gnawed at his body, and he was worried about what the doctor would find. Were the fatigue and cramps signs of a serious illness?

He got up out of his chair and walked to one of the conference rooms. Martinsson was already there, looking clean-cut and tanned. Wallander thought about the time, two years earlier, when Martinsson had come very close to giving up his career. His daughter had been attacked in the playground because her father was a policeman. But he had stuck it out. To Wallander he would always be the young man who had just joined the force, despite the fact that he had worked in Ystad longer than most of them.

They sat down and talked about the weather. After five minutes Martinsson said, "Where the hell is Svedberg?"

His question was justified, since Svedberg was known for his punctuality.

"Did you talk to him?"

"He had already gone when I tried to reach him. But I left a message on his answerphone."

Wallander nodded in the direction of the telephone that stood on the table.

"You should probably give him another call."

Martinsson dialled the number.

"Where are you?" he asked. "We're waiting for you."

He put the receiver down. "I'm just getting the machine."

"He must be on his way," Wallander said. "Let's start without him."

Martinsson leafed through a stack of papers. Then he pushed a postcard over to Wallander. It was an aerial shot of central Vienna.

"This is the card that the Hillström family found in their letter box on Tuesday, 6 August. As you can see, Astrid Hillström says that they're thinking of staying a little longer than they had originally planned. But everything is fine and they all send their regards. She asks her mother to call around and tell everyone that they're well."

Wallander read the card. The handwriting reminded him of Linda's. It was the same round lettering. He put it back.

"Eva Hillström came here, you said."

"She literally burst into my office. We knew she was the nervous type, but this was something else. She's clearly terrified and convinced that she's right."

"What's she so sure of?"

"That something's happened to them. That her daughter didn't write that postcard."

Wallander thought for a moment. "Is it the handwriting? The signature?"

"It resembles Astrid Hillström's writing. But her mother claims it's a very easy style to copy, as is her signature. She's right about that."

Wallander pulled over a notebook and a pen. In less than a minute he had perfected Astrid Hillström's handwriting and signature.

"Eva Hillström is anxious about her daughter's welfare and turns to the police. That's understandable. But if it isn't the handwriting or the signature that's worrying her, then what is it?"

"She couldn't say."

"But you did ask her."

"I asked her about everything. Was there something about the choice of words? Or was there something in the way she put it? She didn't know. But she was certain that her daughter hadn't written the card."

Wallander made a face and shook his head. "It must have been something."

They looked at each other.

"Do you remember what you said to me yesterday?" Wallander asked. "That you were starting to get worried yourself?"

Martinsson nodded. "Something doesn't add up," he said. "I just can't put my finger on it."

"Let's put the question another way," Wallander said. "If they haven't left on this unplanned holiday, then what's happened? And who's writing these cards? We know that their cars and their passports are missing."

"I'm obviously mistaken," Martinsson answered. "I was probably influenced by Eva Hillström's anxiety."

"Parents always worry about their children," Wallander said. "If you only knew how many times I've wondered what Linda was up to. Especially when you get postcards from strange places all around the world."

"So what do we do?" Martinsson asked.

"We continue to keep the situation under surveillance," Wallander said. "But let's go over the facts from the beginning, just to make sure we haven't missed anything."

Martinsson summarised the events in his unfailingly clear fashion. Ann-Britt Höglund had once asked Wallander if he realised that Martinsson had learned how to make presentations by observing him. Wallander had scoffed at this, but Höglund had stood her ground. Wallander still didn't know if it was true.

The chain of events was simple enough. Three people, all between the ages of 20 and 23, decided to celebrate Midsummer's Eve together. One of them, Martin Boge, lived in Simrishamn, while the other two, Lena Norman and Astrid Hillström, came from the western part of Ystad. They were old friends and spent a lot of time together. Their parents were all wealthy. Lena Norman was studying at Lund University while the other two had temporary jobs. None of them had ever had any problems with the law or with drugs. Astrid Hillström and Martin Boge still lived at home; Lena Norman lived in halls of residence in Lund. They didn't tell anyone where they were planning to hold their Midsummer's Eve party. Their parents had talked to one another and to their friends but no one seemed to know anything. This was not unusual, since they were often secretive and never divulged their plans to outsiders. At the time of their disappearance, they had two cars at their disposal: a Volvo and a Toyota. These cars disappeared at the same time as their owners, on the afternoon of 21 June. After that no one had seen them again. The first postcard was sent on 26 June from Hamburg, stating their intention to travel through Europe. A couple of weeks later, Astrid Hillström had sent a second postcard from Paris in which she explained that they were on their way south. And now she had apparently sent a third postcard.

Martinsson stopped talking.

Wallander reflected on what he had said. "What could possibly have gone wrong?" he asked.

"I have no idea."

"Is there any indication of anything out of the ordinary in relation to their disappearance?"

"Not really."

Wallander leaned back in his chair. "The only thing we have is Eva Hillström's anxiety," he said. "A worried mother."