Blomkvist had been fascinated by the old man's account, but when Vanger excused himself to go to the bathroom, his scepticism returned. The old man had still not got to the end, and Blomkvist had finally promised to listen to the whole story.

"What do you think happened to her?" he said when Vanger came back into the room.

"Normally there were some twenty-five people living here year-round, but because of the family gathering there were more than sixty on Hedeby Island that day. Of these, between twenty and twenty-five can be ruled out, pretty much so. I believe that of those remaining, someone - and in all likelihood it was someone from the family - killed Harriet and hid the body."

"I have a dozen objections to that."

"Let's hear them."

"Well, the first one is that even if someone hid her body, it should have been found if the search was as thorough as the one you described."

"To tell you the truth, the search was even more extensive than I've described. It wasn't until I began to think of Harriet as a murder victim that I realised several ways in which her body could have disappeared. I can't prove this, but it's at least within the realm of possibility."

"Tell me."

"Harriet went missing sometime around 3:00 that afternoon. At about 2:55 she was seen by Pastor Falk, who was hurrying to the bridge. At almost exactly the same time a photographer arrived from the local paper, and for the next hour he took a great number of pictures of the drama. We - the police, I mean - examined the photographs and confirmed that Harriet was not in any one of them; but every other person in town was seen in at least one, apart from very small children."

Vanger took out another album and placed it on the table.

"These are pictures from that day. The first one was taken in Hedestad during the Children's Day parade. The same photographer took it around 1:15 p.m., and Harriet is there in it."

The photograph was taken from the second floor of a building and showed a street along which the parade - clowns on trucks and girls in bathing suits - had just passed. Spectators thronged the pavements. Vanger pointed at a figure in the crowd.

"That's Harriet. It's about two hours before she will disappear; she's with some of her schoolfriends in town. This is the last picture taken of her. But there's one more interesting shot."

Vanger leafed through the pages. The album contained about 180 pictures - five rolls - from the crash on the bridge. After having heard the account, it was almost too much to suddenly see it in the form of sharp black-and-white images. The photographer was a professional who had managed to capture the turmoil surrounding the accident. A large number of the pictures focused on the activities around the overturned tanker truck. Blomkvist had no problem identifying a gesticulating, much younger Henrik Vanger soaked with heating oil.

"This is my brother Harald." The old man pointed to a man in shirtsleeves bending forward and pointing at something inside the wreck of Aronsson's car. "My brother Harald may be an unpleasant person, but I think he can be eliminated from the list of suspects. Except for a very short while, when he had to run back here to the farm to change his shoes, he spent the afternoon on the bridge."

Vanger turned some more pages. One image followed another. Focus on the tanker truck. Focus on spectators on the foreshore. Focus on Aronsson's car. General views. Close-ups with a telephoto lens.

"This is the interesting picture," Vanger said. "As far as we could determine it was taken between 3:40 and 3:45, or about 45 minutes after Harriet ran into Falk. Take a look at the house, the middle second floor window. That's Harriet's room. In the preceding picture the window was closed. Here it's open."

"Someone must have been in Harriet's room."

"I asked everyone; nobody would admit to opening the window."

"Which means that either Harriet did it herself, and she was still alive at that point, or else that someone was lying to you. But why would a murderer go into her room and open the window? And why should anyone lie about it?"

Vanger shook his head. No explanation presented itself.

"Harriet disappeared sometime around 3:00 or shortly thereafter. These pictures give an impression of where certain people were at that time. That's why I can eliminate a number of people from the list of suspects. For the same reason I can conclude that some people who were not in the photographs at that time must be added to the list of suspects."

"You didn't answer my question about how you think the body was removed. I realise, of course, that there must be some plausible explanation. Some sort of common old illusionist's trick."

"There are actually several very practical ways it could have been done. Sometime around 3:00 the killer struck. He or she presumably didn't use any sort of weapon - or we would have found traces of blood. I'm guessing that Harriet was strangled and I'm guessing that it happened here - behind the wall in the courtyard, somewhere out of the photographer's line of sight and in a blind spot from the house. There's a path, if you want to take a shortcut, to the parsonage - the last place she was seen - and back to the house. Today there's a small flower bed and lawn there, but in the sixties it was a gravelled area used for parking. All the killer had to do was open the boot of a car and put Harriet inside. When we began searching the island the next day, nobody was thinking that a crime had been committed. We focused on the shorelines, the buildings, and the woods closest to the village."

"So nobody was checking the boots of cars."

"And by the following evening the killer would have been free to get in his car and drive across the bridge to hide the body somewhere else."

"Right under the noses of everyone involved in the search. If that's the way it happened, we're talking about a cold-blooded bastard."

Vanger gave a bitter laugh. "You just gave an apt description of quite a few members of the Vanger family."

They continued their discussion over supper at 6:00. Anna served roast hare with currant jelly and potatoes. Vanger poured a robust red wine. Blomkvist still had plenty of time to make the last train. He thought it was about time to sum things up.

"It's a fascinating story you've been telling me, I admit it. But I still don't know why you wanted me to hear it."

"I told you. I want to nail the swine who murdered Harriet. And I want to hire you to find out who it was."

"Why?"

Vanger put down his knife and fork. "Mikael, for thirty-six years I've driven myself crazy wondering what happened to Harriet. I've devoted more and more of my time to it."

He fell silent and took off his glasses, scrutinising some invisible speck of dirt on the lens. Then he raised his eyes and looked at Blomkvist.

"To be completely honest with you, Harriet's disappearance was the reason why gradually I withdrew from the firm's management. I lost all motivation. I knew that there was a killer somewhere nearby and the worrying and searching for the truth began to affect my work. The worst thing is that the burden didn't get any lighter over time - on the contrary. Around 1970 I had a period when I just wanted to be left alone. Then Martin joined the board of directors, and he had to take on more and more of my work. In 1976 I retired and Martin took over as CEO. I still have a seat on the board, but I haven't sailed many knots since I turned fifty. For the last thirty-six years not a day has passed that I have not pondered Harriet's disappearance. You may think I'm obsessed with it - at least most of my relatives think so."

"It was a horrific event."

"More than that. It ruined my life. That's something I've become more aware of as time has passed. Do you have a good sense of yourself?"

"I think so, yes."

"I do too. I can't forget what happened. But my motives have changed over the years. At first it was probably grief. I wanted to find her and at least have a chance to bury her. It was about getting justice for Harriet."

"In what way has that changed?"

"Now it's more about finding the bastard who did it. But the funny thing is, the older I get, the more of an all-absorbing hobby it has become."

"Hobby?"

"Yes, I would use that word. When the police investigation petered out I kept going. I've tried to proceed systematically and scientifically. I've gathered all the information that could possibly be found - the photographs, the police report, I've written down everything people told me about what they were doing that day. So in effect I've spent almost half my life collecting information about a single day."

"You realise, I suppose, that after thirty-six years the killer himself might be dead and buried?"

"I don't believe that."

Blomkvist raised his eyebrows at the conviction in his voice.

"Let's finish dinner and go back upstairs. There's one more detail before my story is done. And it's the most perplexing of all."

Salander parked the Corolla with the automatic transmission by the commuter railway station in Sundbyberg. She had borrowed the Toyota from Milton Security's motor pool. She had not exactly asked permission, but Armansky had never expressly forbidden her from using Milton's cars. Sooner or later, she thought, I have to get a vehicle of my own. She did own a second-hand Kawasaki 125, which she used in the summertime. During the winter the bike was locked in her cellar.

She walked to Hogklintavagen and rang the bell at 6:00 on the dot. Seconds later the lock on the street door clicked and she went up two flights and rang the doorbell next to the name of Svensson. She had no idea who Svensson might be or if any such person even lived in that apartment.

"Hi, Plague," she said.

"Wasp. You only pop in when you need something."

As usual, it was dark in the apartment; the light from a single lamp seeped out into the hall from the bedroom he used as an office. The man, who was three years older than Salander, was six foot two and weighed 330 pounds. She herself was four feet eleven and weighed 90 pounds and had always felt like a midget next to Plague. The place smelled stuffy and stale.

"It's because you never take a bath, Plague. It smells like a monkey house in here. If you ever went out I could give you some tips on soap. They have it at the Konsum."

He gave her a wan smile, but said nothing. He motioned her to follow him into the kitchen. He plopped down on a chair by the kitchen table without turning on a light. The only illumination came from the street light beyond the window.

"I mean, I may not hold the record in cleaning house either, but if I've got old milk cartons that smell like maggots I bundle them up and put them out."

"I'm on a disability pension," he said. "I'm socially incompetent."

"So that's why the government gave you a place to live and forgot about you. Aren't you ever afraid that your neighbours are going to complain to the inspectors? Then you might fetch up in the funny farm."

"Have you something for me?"

Salander unzipped her jacket pocket and handed him five thousand kronor.

"It's all I can spare. It's my own money, and I can't really deduct you as a dependant."

"What do you want?"

"The electronic cuff you talked about two months ago. Did you get it?"

He smiled and laid a box on the table.

"Show me how it works."

For the next few minutes she listened intently. Then she tested the cuff. Plague might be a social incompetent, but he was unquestionably a genius.

***

Vanger waited until he once more had Blomkvist's attention. Blomkvist looked at his watch and said, "One perplexing detail."

Vanger said: "I was born on November 1. When Harriet was eight she gave me a birthday present, a pressed flower, framed."

Vanger walked around the desk and pointed to the first flower. Bluebell. It had an amateurish mounting.

"That was the first. I got it in 1958." He pointed to the next one. "1959." Buttercup. "1960." Daisy. "It became a tradition. She would make the frame sometime during the summer and save it until my birthday. I always hung them on the wall in this room. In 1966 she disappeared and the tradition was broken."

Vanger pointed to a gap in the row of frames. Blomkvist felt the hairs rise on the back of his neck. The wall was filled with pressed flowers.

"1967, a year after she disappeared, I received this flower on my birthday. It's a violet."

"How did the flower come to you?"

"Wrapped in what they call gift paper and posted in a padded envelope from Stockholm. No return address. No message."

"You mean that..." Blomkvist made a sweeping gesture.

"Precisely. On my birthday every damn year. Do you know how that feels? It's directed at me, precisely as if the murderer wants to torture me. I've worried myself sick over whether Harriet might have been taken away because someone wanted to get at me. It was no secret that she and I had a special relationship and that I thought of her as my own daughter."

"So what is it you want me to do?" Blomkvist said.

When Salander returned the Corolla to the garage under Milton Security, she made sure to go to the toilet upstairs in the office. She used her card key in the door and took the lift straight up to the third floor to avoid going in through the main entrance on the second floor, where the duty officer worked. She used the toilet and got a cup of coffee from the espresso machine that Armansky had bought when at long last he recognised that Salander would never make coffee just because it was expected of her. Then she went to her office and hung her leather jacket over the back of her chair.