By 3.30 p.m. he was on his Way back to the station. He called Martinsson and Svedberg into his office, closed the door and instructed the switchboard to hold his calls.

"This isn't going to be easy," he began. "We can only hope the post-mortems and the forensic team's examination of the life-raft and the clothes come up with something. All the same, there are a few questions I'd like answered straight away."

Svedberg was leaning against the wall, notebook in hand. He was in his 40s and balding, born in Ystad, and rumour had it that he started feeling homesick the minute he left the town. He often gave the impression of being slow and lacking in interest, but he was thorough, and that was something Wallander appreciated. In many ways Martinsson was the opposite of Svedberg: he was coming up to 30, born in Trollhattan, and had set his sights early on a police career. He was also involved in Liberal Party politics, and according to what Wallander had heard, had a good chance of being elected to the local council in the autumn elections. As a police officer, Martinsson was impulsive and sometimes careless, but he often had good ideas and his ambition meant that he worked tirelessly when he thought he could see a solution to a problem.

"I want to know where this life-raft comes from," Wallander said. "When we know how long the two men have been dead, we'll have to try and work out which direction the boat came from, and how far it's drifted."

Svedberg stared at him in surprise.

"Will that be possible?" he asked.

"We must get on to the meteorological office," Wallander said. "They know all there is to know about the weather and the wind. We ought to be able to get a rough idea of where the boat has come from. And I want to know everything we can find out about the life-raft itself. Where it was made, what type of vessels might carry such rafts. Everything."

He nodded towards Martinsson.

"That's your job."

"Shouldn't we begin by running a computer search to see if the men are listed anywhere as missing?" Martinsson asked.

"You can start by doing that," Wallander said. "Get in touch with the coastguards, contact all their stations along the south coast. And see what Björk has to say about bringing in Interpol straight away. It's obvious that if we're going to trace who they are, we'll have to cast our nets wide from the very beginning."

Martinsson nodded and made a note on a sheet of paper. Svedberg chewed thoughtfully on his pencil.

"The forensic team will give the men's clothes a thorough going over," Wallander continued. "They must find some clues."

There was a knock on the door and Norén came in, carrying a rolled-up nautical chart.

"I thought you might need this," he said.

They spread it out over his desk and pored over it, as if planning a naval battle.

"How fast does a life-raft drift?" Svedberg asked. "Currents and winds can slow it down as well as speed it up."

They contemplated the chart in silence. Then Wallander rolled it up again and stood it in the corner behind his chair. Nobody had anything to say.

"Let's get going, then," he said. "We can meet here again at 6 p.m. and see how far we've got."

As Svedberg and Norén left the room, Wallander asked Martinsson to stay behind.

"What did the woman have to say?" he asked.

Martinsson shrugged.

"Mrs Forsell," he said. "A widow. Lives in Mossby. She's a retired teacher from the grammar school in Angelholm. Lives here all the year round with her dog, TegneY. Fancy naming a dog after a poet! Every day they go out for some fresh air on the beach. When she walked along the cliffs last night, there was no sign of a life-raft; but it was there this morning. She saw it at about 10.15 a.m., and called us straight away."

"10.15 a.m.," Wallander said thoughtfully. "Isn't that a bit late to be walking a dog?"

Martinsson nodded.

"That occurred to me as well, but it turned out she'd been out at seven o'clock too, but they walked along the beach in the other direction."

Wallander changed the subject. "The man who rang yesterday," he asked, "what did he sound like?"

"Like I said. Convincing."

"Did he have an accent? Could you tell how old he was?"

"He had a local accent. Like Svedberg's. His voice was hoarse; I wouldn't be surprised to find he's a smoker. In his 40s or 50s, I'd say. He spoke simply and clearly. He could be anything from a bank clerk to a farmer."

Wallander had one more question.

"Why did he ring?"

"I've been wondering that," Martinsson answered. "He might have known the boat would drift ashore because he'd been mixed up in it himself. He might have been the one who did the shooting. He might have seen something, or heard something. There are several possibilities."

"What's the logical explanation?"

"The last one," Martinsson answered without hesitation. "He saw or heard something. This doesn't seem to be the type of murder where the killer would choose to set the police on his trail."

Wallander had come to the same conclusion.

"Let's go a step further," he said. "Seen or heard something? Two men dead in a life-raft? If he isn't involved, he can hardly have seen the murder or murders. That means he must have seen the raft."

"A life-raft drifting at sea," Martinsson said. "How do you see something like that? Only by being in a boat yourself."

"Exactly," Wallander said. "Precisely. But if he didn't do it, why does he want to remain anonymous?"

"Some people prefer not to get involved in things," Martinsson said. "You know how it is."

"Could be. But there might be another explanation. He might have quite a different reason for not wanting to get mixed up with the police."

"Isn't that a bit far-fetched?"

"I'm only thinking aloud," Wallander said. "Somehow or other we have to trace that man."

"Shall we send out an appeal for him to get in touch with us again?"

"Yes," Wallander said. "Not today, though. I want to find out more about the dead men first."

Wallander drove to the hospital. He'd been there many times, but he still had trouble finding the newly built complex. He paused in the cafeteria on the ground floor and bought a banana, then went upstairs to the pathology department. The pathologist, whose name was Mörth, hadn't yet started the detailed examination of the corpses. Even so, he was able to answer Wallander's first question.

"Both men were shot," he stated. "At close range, through the heart. I assume that is the cause of death."

"I'd like to see your report as soon as possible," Wallander said. "Is there anything you can say now about the time of death?"

Mörth shook his head.

"No," he said. "Mind you, that's an answer in a way." "Meaning what?"

"That they've probably been dead for quite a long time. That makes it more difficult to pin down the precise time of death."

"Two days? Three? A week?"

"I can't answer that," Mörth said, "and I don't want to guess."

He disappeared into the lab. Wallander took off his jacket, put on a pair of rubber gloves, and started to go through the men's clothes, which were laid out on what looked like an old-fashioned kitchen sink.

One of the suits was made in England, the other in Belgium. The shoes were Italian, and it seemed to Wallander that they were expensive. Shirts, ties and underwear told the same story: they were good quality, certainly not cheap. When Wallander had finished examining the clothes twice, he realised he was unlikely to get any further. All he knew was that in all probability, the two men were not short of money. But where were the wallets? Wedding rings? Watches? Even more bewildering was the fact that the men had not been wearing their jackets when they were shot. There were no holes or powder burns on them.

Wallander tried to conjure up the scene. Somebody shoots two men straight through the heart. When they're dead, whoever did it then puts their jackets on before dumping the bodies into a life-raft. Why?