Blomkvist tried the door. It was locked. He thought for a moment, then told Salander to sit down and wait for him. He walked over to see Anna Nygren and knocked. He explained that he wanted to have a closer look at the family crypt, and he wondered where Henrik might keep the key. Anna looked doubtful, but she collected the key from his desk.

As soon as they opened the door, they knew that they had been right. The stench of burned cadaver and charred remains hung heavy in the air. But the cat torturer had not made a fire. In one corner stood a blowtorch, the kind used by skiers to melt the wax on their skis. Salander got the camera out of the pocket of her jeans skirt and took some pictures. Then, gingerly, she picked up the blowtorch.

"This could be evidence. He might have left fingerprints," she said.

"Oh sure, we can ask the Vanger family to line up and give us their fingerprints." Blomkvist smiled. "I would love to watch you get Isabella's."

"There are ways," Salander said.

There was a great deal of blood on the floor, not all of it dry, as well as a bolt cutter, which they reckoned had been used to cut off the cat's head.

Blomkvist looked around. A raised sarcophagus belonged to Alexandre Vangeersad, and four graves in the floor housed the remains of the earliest family members. More recently the Vangers had apparently settled for cremation. About thirty niches on the wall had the names of the clan ancestors. Blomkvist traced the family chronicle forward in time, wondering where they buried family members who were not given space inside the crypt - those not deemed important enough.

"Now we know," Blomkvist said as they were re-crossing the bridge. "We're hunting for the complete lunatic."

"What do you mean?"

Blomkvist paused in the middle of the bridge and leaned on the rail.

"If this was some run-of-the-mill crackpot who was trying to frighten us, he would have taken the cat down to the garage or even out into the woods. But he went to the crypt. There's something compulsive about that. Just think of the risk. It's summer and people are out and about at night, going for walks. The road through the cemetery is a main road between the north and south of Hedeby. Even if he shut the door behind him, the cat must have raised Cain, and there must have been a burning smell."

"He?"

"I don't think that Cecilia Vanger would be creeping around here in the night with a blowtorch."

Salander shrugged.

"I don't trust any last one of them, including Frode or your friend Henrik. They're all part of a family that would swindle you if they had the chance. So what do we do now?"

Blomkvist said, "I've discovered a lot of secrets about you. How many people, for example, know that you're a hacker?"

"No-one."

"No-one except me, you mean."

"What are you getting at?"

"I want to know if you're OK with me. If you trust me."

She looked at him for a long moment. Finally, for an answer, she only shrugged.

"There's nothing I can do about it."

"Do you trust me?" Blomkvist persisted.

"For the time being," she said.

"Good. Let's go over to see Frode."

This was the first time Advokat Frode's wife had met Salander. She gave her a wide-eyed look at the same time as she smiled politely. Frode's face lit up when he saw Salander. He stood to welcome them.

"How nice to see you," he said. "I've been feeling guilty that I never properly expressed my gratitude for the extraordinary work you did for us. Both last winter and now, this summer."

Salander gave him a suspicious glare.

"I was paid," she said.

"That's not it. I made some assumptions about you when I first saw you. You would be kind to pardon me in retrospect."

Blomkvist was surprised. Frode was capable of asking a twenty-five-year-old pierced and tattooed girl to forgive him for something for which he had no need to apologise! The lawyer climbed a few notches in Blomkvist's eyes. Salander stared straight ahead, ignoring him.

Frode looked at Blomkvist.

"What did you do to your head?"

They sat down. Blomkvist summed up the developments of the past twenty-four hours. As he described how someone had shot at him out near the Fortress, Frode leaped to his feet.

"This is barking mad." He paused and fixed his eyes on Blomkvist. "I'm sorry, but this has to stop. I can't have it. I am going to talk to Henrik and break the contract."

"Sit down," said Blomkvist.

"You don't understand..."

"What I understand is that Lisbeth and I have got so close that whoever is behind all of this is reacting in a deranged manner, in panic. We've got some questions. First of all: how many keys are there to the Vanger family crypt and who has one?"

"It's not my province, and I have no idea," Frode said. "I would suppose that several family members would have access to the crypt. I know that Henrik has a key, and that Isabella sometimes goes there, but I can't tell you whether she has her own key or whether she borrows Henrik's."

"OK. You're still on the main board. Are there any corporate archives? A library or something like that, where they've collected press clippings and information about the firm over the years?"

"Yes, there is. At the Hedestad main office."

"We need access to it. Are there any old staff newsletters or anything like that?"

"Again I have to concede that I don't know. I haven't been to the archives myself in thirty years. You need to talk to a woman named Bodil Lindgren."

"Could you call her and arrange that Lisbeth has access to the archives this afternoon? She needs all the old press clippings about the Vanger Corporation."

"That's no problem. Anything else?"

"Yes. Greger Vanger was holding a Hasselblad in his hand on the day the bridge accident occurred. That means that he also might have taken some pictures. Where would the pictures have ended up after his death?"

"With his widow or his son, logically. Let me call Alexander and ask him."

"What am I looking for?" Salander said when they were on their way back to the island.

"Press clippings and staff newsletters. I want you to read through everything around the dates when the murders in the fifties and sixties were committed. Make a note of anything that strikes you. Better if you do this part of the job. It seems that your memory..."

She punched him in the side.

Five minutes later her Kawasaki was clattering across the bridge.

Blomkvist shook hands with Alexander Vanger. He had been away for most of the time that Blomkvist had been in Hedeby. He was twenty when Harriet disappeared.

"Dirch said that you wanted to look at old photographs."

"Your father had a Hasselblad, I believe."

"That's right. It's still here, but no-one uses it."

"I expect you know that Henrik has asked me to study again what happened to Harriet."

"That's what I understand. And there are plenty of people who aren't happy about that."

"Apparently so, and of course you don't have to show me anything."

"Please... What would you like to see?"

"If your father took any pictures on the day of the accident, the day that Harriet disappeared."

They went up to the attic. It took several minutes before Alexander was able to identify a box of unsorted photographs.

"Take home the whole box," he said. "If there are any at all, they'll be in there."

As illustrations for the family chronicle, Greger Vanger's box held some real gems, including a number of Greger together with Sven Olof Lindholm, the big Swedish Nazi leader in the forties. Those he set aside.

He found envelopes of pictures that Greger had taken of family gatherings as well as many typical holiday photographs - fishing in the mountains and a journey in Italy.

He found four pictures of the bridge accident. In spite of his exceptional camera, Greger was a wretched photographer. Two pictures were close-ups of the tanker truck itself, two were of spectators, taken from behind. He found only one in which Cecilia Vanger was visible in semi-profile.

He scanned in the pictures, even though he knew that they would tell him nothing new. He put everything back in the box and had a sandwich lunch as he thought things over. Then he went to see Anna.

"Do you think Henrik had any photograph albums other than the ones he assembled for his investigation about Harriet?"

"Yes, Henrik has always been interested in photography - ever since he was young, I've been told. He has lots of albums in his office."

"Could you show me?"

Her reluctance was plain to see. It was one thing to lend Blomkvist the key to the family crypt - God was in charge there, after all - but it was another matter to let him into Henrik Vanger's office. God's writ did not extend there. Blomkvist suggested that Anna should call Frode. Finally she agreed to allow him in. Almost three feet of the very bottom shelf was taken up with photograph albums. He sat at the desk and opened the first album.

Vanger had saved every last family photograph. Many were obviously from long before his time. The oldest pictures dated back to the 1870s, showing gruff men and stern women. There were pictures of Vanger's parents. One showed his father celebrating Midsummer with a large and cheerful group in Sandhamn in 1906. Another Sandhamn photograph showed Fredrik Vanger and his wife, Ulrika, with Anders Zorn and Albert Engstrom sitting at a table. Other photographs showed workers on the factory floor and in offices. He found Captain Oskar Granath who had transported Vanger and his beloved Edith Lobach to safety in Karlskrona.

Anna came upstairs with a cup of coffee. He thanked her. By then he had reached modern times and was paging through images of Vanger in his prime, opening factories, shaking hands with Tage Erlander, one of Vanger and Marcus Wallenberg - the two capitalists staring grimly at each other.

In the same album he found a spread on which Vanger had written in pencil "Family Council 1966." Two colour photographs showed men talking and smoking cigars. He recognised Henrik, Harald, Greger, and several of the male in-laws in Johan Vanger's branch of the family. Two photographs showed the formal dinner, forty men and women seated at the table, all looking into the camera. The pictures were taken after the drama at the bridge was over but before anyone was aware that Harriet had disappeared. He studied their faces. This was the dinner she should have attended. Did any of the men know that she was gone? The photographs provided no answer.

Then suddenly he choked on his coffee. He started coughing and sat up straight in his chair.

At the far end of the table sat Cecilia Vanger in her light-coloured dress, smiling into the camera. Next to her sat another blonde woman with long hair and an identical light-coloured dress. They were so alike that they could have been twins. And suddenly the puzzle piece fell into place. Cecilia wasn't the one in Harriet's window - it was her sister, Anita, two years her junior and now living in London.

What was it Salander had said? Cecilia Vanger is in a lot of the pictures. Not at all. There were two girls, and as chance would have it - until now - they had never been seen in the same frame. In the black-and-white photographs, from a distance, they looked identical. Vanger had presumably always been able to tell the sisters apart, but for Blomkvist and Salander the girls looked so alike that they had assumed it was one person. And no-one had ever pointed out their mistake because they had never thought to ask.

Blomkvist turned the page and felt the hairs on the back of his neck stand on end. It was as if a cold gust of wind passed through the room.

There were pictures taken the next day, when the search for Harriet had begun. A young Inspector Morell was giving instructions to a search party consisting of two uniformed police officers and ten men wearing boots who were about to set out. Vanger was wearing a knee-length raincoat and a narrow-brimmed English hat.

On the left of the photograph stood a young, slightly stout young man with light, longish hair. He had on a dark padded jacket with a red patch at the shoulder. The image was very clear. Blomkvist recognised him at once - and the jacket - but, just to make sure, he removed the photograph and went down to ask Anna if she recognised the man.

"Yes, of course, that's Martin."

Salander ploughed through year after year of press cuttings, moving in chronological order. She began in 1949 and worked her way forward. The archive was huge. The company was mentioned in the media nearly every day during the relevant time period - not only in the local press but also in the national media. There were financial analyses, trade union negotiations, the threat of strikes, factory openings and factory closings, annual reports, changes in managers, new products that were launched... There was a flood of news. Click. Click. Click. Her brain was working at high speed as she focused and absorbed the information from the yellowing pages.

After several hours she had an idea. She asked the archives manager if there was a chart showing where the Vanger Corporation had factories or companies during the fifties and sixties.

Bodil Lindgren looked at Salander with undisguised coldness. She was not at all happy giving a total stranger permission to enter the inner sanctum of the firm's archives, being obliged to allow her to look through whatever documents she liked. And besides, this girl looked like some sort of half-witted fifteen-year-old anarchist. But Herr Frode had given her instructions that could not be misinterpreted. This slip of a girl was to be free to look at anything she pleased. And it was urgent. She brought out the printed annual reports for the years that Salander wanted to see; each report contained a chart of the firm's divisions throughout Sweden.