She didn't believe him, and he was too tired to go into more detail. The important thing was that he knew it. Still, he owed her an explanation. She had helped him. Although it was past midnight, he continued to explain.

"When she went into the lavatory, she took off her makeup and the wig, and then she walked out again," Wallander said. "She probably altered something about the way her clothing looked as well. Neither of us noticed anything, because we were waiting for a woman to come out. Who would have noticed a man?"

"The Amigo doesn't have a reputation as a transvestite bar."

"He may simply have gone there to play the role of a woman," Wallander said thoughtfully. "Not to be among his own kind."

"What does this mean for your investigation?"

"I don't know. It probably means a great deal, but I haven't thought it through yet."

She looked down at her watch.

"The last boat to Malmö has already left. The earliest leaves at 4.45 a.m. in the morning."

"I'll stay in a hotel," Wallander said.

She shook her head. "You can sleep on the sofa at my place," she said. "My husband comes home around this time. He's a waiter. We have sandwiches and a beer together before we go to bed."

They left the police station.

Wallander slept uneasily. At one point he got up and walked over to the window. He stared down at the empty street and wondered why all city streets resembled each other at night. He kept waiting for someone to appear, but all was quiet. He felt his anxiety grow stronger. The victims so far had been dressed up in costume. Just like Louise. When Wallander had told her who he was, she left.

It was him, he thought. There's no other explanation. I had the killer by my side without knowing it. But I didn't manage to see through his disguise, and he disappeared. Now he knows we're closing in, but he also knows we haven't guessed his real identity.

Wallander went back to the sofa and dozed until it was time to take the ferry back to Malmö.

He called Birch when he got to the other side, hoping he was an early riser. Birch answered and said he was just drinking his morning coffee.

"What happened to you last night? I thought we were going to be in touch."

Wallander explained what had happened.

"Were you really that close?"

"I let myself be fooled. I should have stood guard by the lavatories."

"It's easy to say so in hindsight," Birch said. "You're back in Malmö now, aren't you? You must be tired."

"The worst thing is that I can't get the car started. I left my lights on."

"I'll come over. I have jump leads," Birch said. "Where are you?"

Wallander gave him directions.

It took Birch less than 20 minutes to get there, during which time Wallander napped in his car.

Birch looked closely at Wallander. "You should really try to sleep for a few hours," he said. "It won't help matters if you collapse."

While they put the jump leads on, Birch told him he had searched Haag's flat but hadn't found anything significant.

"We'll do another search of the studio and his flat," Birch said. "And we'll stay in touch."

"I'll tell you how things go at our end," Wallander said.

He left Malmö. It was 6.25 a.m. At the turn-off for Jägersro, he pulled over to the side of the road and called Martinsson.

"I've been trying to reach you," Martinsson said. "We were supposed to have a meeting last night, but no one could contact you."

"I was in Denmark," Wallander said. "Tell everyone I want a meeting at 8 a.m."

"Has anything happened?"

"Yes, but I'll tell you about it later."

Wallander continued on towards Ystad. The weather was still beautiful. There were no clouds in the sky and no wind. He was feeling less tired, and his mind was starting to work again. He went through the meeting with Louise over and over, trying to home in on the face behind the wig and make-up. Sometimes he almost had it.

He reached Ystad at 7.40 a.m. Ebba was at the front desk. She sneezed.

"Caught a cold?" he asked. "In the middle of summer?"

"Even an old bag like me can have allergies," she replied good-naturedly. Then she looked sternly at him.

"You haven't had a wink of sleep, have you?"

"I was in Copenhagen. That's not conducive to a good night's sleep."

She didn't seem to see the humour in this. "If you don't start taking your health seriously, you'll pay for it," she said. "Mark my words."

He didn't answer. He was sometimes annoyed by her ability to see right through him. She was right, of course. He thought about the clumps of sugar in his bloodstream.

He got himself a cup of coffee and went into his office. Soon his colleagues would be waiting for him in the conference room. He would have to tell them what had happened the night before, how the killer had been there, gone to the lavatory, and disappeared.

A woman went up in smoke by taking on the form of a man. There was no Louise any more. All they had was an unknown man who simply removed his wig and disappeared without a trace. A man who had already killed eight people, and who might be preparing to strike again.

He thought about Isa Edengren, curled up in the cave behind the ferns, and shivered.

What do I tell them, Wallander thought. How do I find the right path through this unknown territory? We're pressed for time and can't afford to think through every possibility, every possible lead. How can I know which is the right way?

Wallander left his own questions unanswered and went to the men's room. He stared at his image in the mirror. He was swollen and pale, with watery bags under his eyes. For the first time in his life, the sight of his face made him nauseated.

I have to catch this killer, he thought. If only so I can go on medical leave and start taking control of my health.

It was now just after 8 a.m. Wallander left the men's room.

Everyone was already in the conference room when he entered. He felt like the tardy schoolboy, or perhaps the flustered teacher. There was Thurnberg, fingering his perfectly knotted tie. Holgersson smiled her quick, nervous smile. The others greeted him to the best of their exhausted capability: simply by being there.

Wallander sat down and told them exactly where things stood. How he had been inches away from the killer, and how he had let him slip away under his very nose. He told the story calmly, starting with Maria Hjortberg and ending with Louise's smile and her apparent willingness to talk to him, saying she just had to visit the lavatory first.

"He must have removed the wig while he was in there," he said. "It was the same one as in the picture, by the way. He must have wiped off his make-up as well. He's careful by nature, and he must have foreseen the risk of being recognised. He probably had some make-up remover with him. I didn't notice him slip out because I was waiting for a woman."

"What about his clothes?" Höglund said.

"Some kind of trouser suit," Wallander said. "And low-heeled shoes. I suppose it might have been obvious that he was a man if one knew to look carefully. But you couldn't see while he sat at the bar."

Höglund's was the only question.

"I have no doubts that he's the one," Wallander said after a pause. "Why else would he leave like that?"

"Did you consider the fact that he might have been on your boat this morning?" Hansson asked.

"I did think of it," Wallander said. "But by then it was too late."

They should blame me for this, he thought. For this and for many other aspects of the investigation. I should have known it was a wig from the moment I first saw the photograph. If we had known we were looking for a man from the beginning it would all have been different. The search for him would have taken precedence over everything else. But I didn't see it. I didn't understand what I was looking at.