The old man went back to his chair.

“The accident actually had nothing to do with Harriet. But it was significant in a crucial way. A shambles ensued: people on both sides of the bridge hurried to try to help; the risk of fire was significant and a major alarm was sounded. Police officers, an ambulance, the rescue squad, the fire brigade, reporters and sightseers arrived in rapid succession. Naturally all of them assembled on the mainland side; here on the island side we did what we could to get Aronsson out of the wreck, which proved to be damnably difficult. He was pinned in and seriously injured.

“We tried to prise him loose with our bare hands, and that didn’t work. He would have to be cut or sawed out, but we couldn’t do anything that risked striking a spark; we were standing in the middle of a sea of oil next to a tanker truck lying on its side. If it had exploded we would have all been killed. It took a long time before we could get help from the mainland side; the truck was wedged right across the bridge, and climbing over it would have been the same as climbing over a bomb.”

Blomkvist could not resist the feeling that the old man was telling a meticulously rehearsed story, deliberately to capture his interest. The man was an excellent storyteller, no question. On the other hand, where was the story heading?

“What matters about the accident is that the bridge was blocked for twenty-four hours. Not until Sunday evening was the last of the oil pumped out, and then the truck could be lifted up by crane and the bridge opened for traffic. During these twenty-four hours Hedeby Island was to all intents and purposes cut off from the rest of the world. The only way to get across to the mainland was on a fireboat that was brought in to transport people from the small-boat harbour on this side to the old harbour below the church. For several hours the boat was used only by rescue crews-it wasn’t until quite late on Saturday night that stranded islanders began to be ferried across. Do you understand the significance of this?”

“I assume that something happened to Harriet here on the island,” Blomkvist said, “and that the list of suspects consists of the finite number of people trapped here. A sort of locked-room mystery in island format?”

Vanger smiled ironically. “Mikael, you don’t know how right you are. Even I have read my Dorothy Sayers. These are the facts: Harriet arrived here on the island about 2:10. If we also include children and unmarried guests, all in all about forty family members arrived in the course of the day. Along with servants and residents, there were sixty-four people either here or near the farm. Some of them-the ones who were going to spend the night-were busy getting settled in neighbouring farms or in guest rooms.

“Harriet had previously lived in a house across the road, but given that neither Gottfried nor Isabella was consistently stable, and one could clearly see how that upset the girl, undermined her studies and so on, in 1964, when she was fourteen, I arranged for her to move into my house. Isabella probably thought that it was just fine to be spared the responsibility for her daughter. Harriet had been living here for the past two years. So this is where she came that day. We know that she met and exchanged some words with Harald in the courtyard-he’s one of my older brothers. Then she came up the stairs, to this room, and said hello to me. She said that she wanted to talk to me about something. Right then I had some other family members with me and I couldn’t spare the time for her. But she seemed anxious and I promised I’d come to her room when I was free. She left through that door, and that was the last time I saw her. A minute or so later there was the crash on the bridge and the bedlam that followed upset all our plans for the day.”

“How did she die?”

“It’s more complicated than that, and I have to tell the story in chronological order. When the accident occurred, people dropped whatever they were doing and ran to the scene. I was…I suppose I took charge and was feverishly occupied for the next few hours. Harriet came down to the bridge right away-several people saw her-but the danger of an explosion made me instruct anyone who wasn’t involved in getting Aronsson out of his car to stay well back. Five of us remained. There were myself and my brother Harald. There was a man named Magnus Nilsson, one of my workers. There was a sawmill worker named Sixten Nordlander who had a house down by the fishing harbour. And there was a fellow named Jerker Aronsson. He was only sixteen, and I should really have sent him away, but he was the nephew of Gustav in the car.

“At about 2:40 Harriet was in the kitchen here in the house. She drank a glass of milk and talked briefly to Astrid, our cook. They looked out of the window at the commotion down at the bridge.

“At 2:55 Harriet crossed the courtyard. She was seen by Isabella. About a minute later she ran into Otto Falk, the pastor in Hedeby. At that time the parsonage was where Martin Vanger has his villa today, and the pastor lived on this side of the bridge. He had been in bed, nursing a cold, when the accident took place; he had missed the drama, but someone had telephoned and he was on his way to the bridge. Harriet stopped him on the road and apparently wanted to say something to him, but he waved her off and hurried past. Falk was the last person to see her alive.”

“How did she die?” Blomkvist said again.

“I don’t know,” Vanger said with a troubled expression. “We didn’t get Aronsson out of his car until around 5:00-he survived, by the way, although he was not in good shape-and sometime after 6:00 the threat of fire was considered past. The island was still cut off, but things began to calm down. It wasn’t until we sat down at the table to have our longdelayed dinner around 8:00 that we discovered Harriet was missing. I sent one of the cousins to get Harriet from her room, but she came back to say that she couldn’t find her. I didn’t think much about it; I probably assumed she had gone for a walk or she hadn’t been told that dinner was served. And during the evening I had to deal with various discussions and arguments with the family. So it wasn’t until the next morning, when Isabella went to find her, that we realised that nobody knew where Harriet was and that no-one had seen her since the day before.” He spread his arms out wide. “And from that day, she has been missing without a trace.”

“Missing?” Blomkvist echoed.

“For all these years we haven’t been able to find one microscopic scrap of her.”

“But if she vanished, as you say, you can’t be sure that she was murdered.”

“I understand the objection. I’ve had thoughts along the same lines. When a person vanishes without a trace, one of four things could have happened. She could have gone off of her own free will and be hiding somewhere. She could have had an accident and died. She could have committed suicide. And finally, she could have been the victim of a crime. I’ve weighed all these possibilities.”

“But you believe that someone took Harriet’s life. Why?”

“Because it’s the only reasonable conclusion.” Vanger held up one finger. “From the outset I hoped that she had run away. But as the days passed, we all realised that this wasn’t the case. I mean, how would a sixteen-year-old from such a protected world, even a very able girl, be able to manage on her own? How could she stay hidden without being discovered? Where would she get money? And even if she got a job somewhere, she would need a social security card and an address.”

He held up two fingers.

“My next thought was that she had had some kind of accident. Can you do me a favour? Go to the desk and open the top drawer. There’s a map there.”

Blomkvist did as he was asked and unfolded the map on the coffee table. Hedeby Island was an irregularly shaped land mass about two miles long with a maximum width of about one mile. A large part of the island was covered by forest. There was a built-up area by the bridge and around the little summer-house harbour. On the other side of the island was the smallholding, Östergården, from which the unfortunate Aronsson had started out in his car.