The Hedestad Courier was founded in 1922, and the pictures department had existed since 1937. The Courier's attic storeroom contained about 1,200 binders, arranged, as Blomberg said, by date. The negatives from September 1966 were kept in four cheap cardboard storage binders.

"How do we go about this?" Blomkvist said. "I really need to sit at a light table and be able to make copies of anything that might be of interest."

"We don't have a darkroom any more. Everything is scanned in. Do you know how to work a negative scanner?"

"Yes, I've worked with images and have an Agfa neg. scanner of my own. I work in PhotoShop."

"Then you use the same equipment we do."

Blomberg took him on a quick tour of the small office, gave him a chair at a light table, and switched on a computer and scanner. She showed him where the coffee machine was in the canteen area. They agreed that Blomkvist could work by himself, but that he had to call her when he wanted to leave the office so that she could come in and set the alarm system. Then she left him with a cheerful "Have fun."

The Courier had had two photographers back then. The one who had been on duty that day was Kurt Nylund, whom Blomkvist actually knew. Nylund was in his twenties in 1966. Then he moved to Stockholm and became a famous photographer working both freelance and as an employee of Scanpix Sweden in Marieberg. Blomkvist had crossed paths with Kurt Nylund several times in the nineties, when Millennium had used images from Scanpix. He remembered him as an angular man with thinning hair. On the day of the parade Nylund had used a daylight film, not too fast, one which many news photographers used.

Blomkvist took out the negatives of the photographs by the young Nylund and put them on the light table. With a magnifying glass he studied them frame by frame. Reading negatives is an art form, requiring experience, which Blomkvist lacked. To determine whether the photograph contained information of value he was going to have to scan in each image and examine it on the computer screen. That would take hours. So first he did a quite general survey of the photographs he might be interested in.

He began by running through all the ones that had been taken of the accident. Vanger's collection was incomplete. The person who had copied the collection - possibly Nylund himself - had left out about thirty photographs that were either blurred or of such poor quality that they were not considered publishable.

Blomkvist switched off the Courier's computer and plugged the Agfa scanner into his own iBook. He spent two hours scanning in the rest of the images.

One caught his eye at once. Some time between 3:10 and 3:15 p.m., just at the time when Harriet vanished, someone had opened the window in her room. Vanger had tried in vain to find out who it was. Blomkvist had a photograph on his screen that must have been taken at exactly the moment the window was opened. There were a figure and a face, albeit out of focus. He decided that a detailed analysis could wait until he had first scanned all the images.

Then he examined the images of the Children's Day celebrations. Nylund had put in six rolls, around two hundred shots. There was an endless stream of children with balloons, grown-ups, street life with hot dog vendors, the parade itself, an artist on a stage, and an award presentation of some sort.

Blomkvist decided to scan in the entire collection. Six hours later he had a portfolio of ninety images, but he was going to have to come back.

At 9:00 he called Blomberg, thanked her, and took the bus home to Hedeby Island.

He was back at 9:00 on Sunday morning. The offices were still empty when Blomberg let him in. He had not realised that it was the Whitsuntide holiday weekend, and that there would not be a newspaper until Tuesday. He spent the entire day scanning images. At 6:00 in the evening there were still forty shots left of Children's Day. Blomkvist had inspected the negatives and decided that close-ups of cute children's faces or pictures of a painter appearing on stage were simply not germane to his objective. What he had scanned in was the street life and crowds.

***

Blomkvist spent the Whitsuntide holiday going over the new material. He made two discoveries. The first filled him with dismay. The second made his pulse beat faster.

The first was the face in Harriet Vanger's window. The photograph had a slight motion blur and was thus excluded from the original set. The photographer had stood on the church hill and sighted towards the bridge. The buildings were in the background. Mikael cropped the image to include the window alone, and then he experimented with adjusting the contrast and increasing the sharpness until he achieved what he thought was the best quality he could get.

The result was a grainy picture with a minimal greyscale that showed a curtain, part of an arm, and a diffuse half-moon-shaped face a little way inside the room.

The face was not Harriet Vanger's, who had raven-black hair, but a person with lighter hair colour.

It was impossible to discern clear facial features, but he was certain it was a woman; the lighter part of the face continued down to shoulder level and indicated a woman's flowing hair, and she was wearing light-coloured clothes.

He calculated her height in relation to the window: it was a woman about five foot seven.

He clicked on to other images from behind the accident and one person fitted the description - the twenty-year-old Cecilia Vanger.

Nylund had taken eighteen shots from the window of Sundstrom's Haberdashery. Harriet was in seventeen of them.

She and her classmates had arrived at Jarnvagsgatan at the same time Nylund had begun taking his pictures. Blomkvist reckoned that the photographs were shot over a period of five minutes. In the first pictures, Harriet and her friends were coming down the street into the frame. In photographs 2-7 they were standing still and watching the parade. Then they had moved about six yards down the street. In the last picture, which may have been taken after some time had passed, the girls had gone.

Blomkvist edited a series of pictures in which he cropped the top half of Harriet and processed them to achieve the best contrast. He put the pictures in a separate folder, opened the Graphic Converter programme, and started the slide show function. The effect was a jerky silent film in which each image was shown for two seconds.

Harriet arrives, image in profile. Harriet stops and looks down at the street. Harriet turns her face towards the street. Harriet opens her mouth to say something to her friend. Harriet laughs. Harriet touches her ear with her left hand. Harriet smiles. Harriet suddenly looks surprised, her face at a 20 0  angle to the left of the camera. Harriet's eyes widen and she has stopped smiling. Harriet's mouth becomes a thin line. Harriet focuses her gaze. In her face can be read... what? Sorrow, shock, fury? Harriet lowers her eyes. Harriet is gone.

Blomkvist played the sequence over and over.

It confirmed with some force the theory he had formulated. Something happened on Jarnvagsgatan.

She sees something - someone - on the other side of the street. She reacts with shock. She contacts Vanger for a private conversation which never happens. She vanishes without a trace.

Something happened, but the photographs did not explain what.

At 2:00 on Tuesday morning Blomkvist had coffee and sandwiches at the kitchen bench. He was simultaneously downhearted and exhilarated. Against all expectations he had turned up new evidence. The only problem was that although it shed light on the chain of events it brought him not one iota closer to solving the mystery.

He thought long and hard about what role Cecilia Vanger might have played in the drama. Vanger had relentlessly charted the activities of all persons involved that day, and Cecilia had been no exception. She was living in Uppsala, but she arrived in Hedeby two days before that fateful Saturday. She stayed with Isabella Vanger. She had said that she might possibly have seen Harriet early that morning, but that she had not spoken to her. She had driven into Hedestad on some errand. She had not seen Harriet there, and she came back to Hedeby Island around 1:00, about the time Nylund was taking his pictures on Jarnvagsgatan. She changed and at about 2:00 helped to set the table for the banquet that evening.

As an alibi - if that is what it was - it was rather feeble. The times were approximate, especially the matter of when she had got back to Hedeby Island, but Vanger had not found anything to indicate that she was lying. Cecilia Vanger was one of those people in the family that Vanger liked best. And she had been his lover. How could he be objective? He certainly could not imagine her as a murderer.

Now a hitherto unknown photograph was telling him that she had lied when she said that she had never been in Harriet's room that day. Blomkvist wrestled with the possible significance of that.

And if you lied about that, what else did you lie about?

He went through in his mind what he knew about Cecilia. An introverted person obviously affected by her past. Lived alone, had no sex life, had difficulty getting close to people. Kept her distance, and when she let loose there was no restraint. She chose a stranger for a lover. Had said that she ended it because she was unable to live with the idea that he would go from her life as unexpectedly as he had appeared. Blomkvist supposed that the reason she had dared to start an affair with him was precisely that he was only there for a while. She did not have to be afraid he would change her life in any long-term way.

He sighed and pushed the amateur psychology aside.

He made the second discovery during the night. The key to the mystery was what it was that Harriet had seen in Hedestad. He would never find that out unless he could invent a time machine and stand behind her, looking over her shoulder.

And then he had a thought. He slapped his forehead and opened his iBook. He clicked on to the uncropped images in the series on Jarnvagsgatan and... there!

Behind Harriet and about a yard to her right were a young couple, the man in a striped sweater and the woman in a pale jacket. She was holding a camera. When Blomkvist enlarged the image it looked to be a Kodak Instamatic with flash - a cheap holiday camera for people who know nothing about photography.

The woman was holding the camera at chin level. Then she raised it and took a picture of the clowns, just as Harriet's expression changed.

Blomkvist compared the camera's position with Harriet's line of vision. The woman had taken a picture of exactly what Harriet was looking at.

His heart was beating hard. He leaned back and plucked his cigarettes out of his breast pocket. Someone had taken a picture. How would he identify and find the woman? Could he get hold of her snapshot? Had the roll ever been developed, and if so did the prints still exist?

He opened the folder with Nylund's photographs from the crowd. For the next couple of hours he enlarged each one and scrutinised it one square inch at a time. He did not see the couple again until the very last pictures. Nylund had photographed another clown with balloons in his hand posing in front of his camera and laughing heartily. The photographs were taken in a car park by the entrance to the sports field where the celebration was being held. It must have been after 2:00 in the afternoon. Right after that Nylund had received the alarm about the crash on the bridge and brought his portraits of Children's Day to a rapid close.

The woman was almost hidden, but the man in the striped sweater was clearly visible, in profile. He had keys in his hand and was bending to open a car door. The focus was on the clown in the foreground, and the car was a bit fuzzy. The number plate was partly hidden but he could see that it started with "AC3."

Number plates in the sixties began with a code indicating the county, and as a child Blomkvist had memorised the county codes. "AC" was for Vasterbotten.

Then he spotted something else. On the back window was a sticker of some sort. He zoomed in, but the text dissolved in a blur. He cropped out the sticker and adjusted the contrast and sharpness. It took him a while. He still could not read the words, but he attempted to figure out what the letters were, based on the fuzzy shapes. Many letters looked surprisingly similar. An "O" could be mistaken for a "D," a "B" for an "E," and so on. After working with a pen and paper and excluding certain letters, he was left with an unreadable text, in one line.

R Jo NI K RIFA RIK

He stared at the image until his eyes began to water. Then he saw the text. "NORSJo SNICKERIFABRIK," followed by figures in a smaller size that were utterly impossible to read, probably a telephone number.

CHAPTER 17

Wednesday, June 11 - Saturday, June 14

Blomkvist got help with the third jigsaw piece from an unexpected quarter.

After working on the images practically all night he slept heavily until well into the afternoon. He awoke with a headache, took a shower, and walked to Susanne's for breakfast. He ought to have gone to see Vanger and report what he had discovered. Instead, when he came back, he went to Cecilia's house and knocked on the door. He needed to ask her why she had lied to him about being in Harriet's room. No-one came to the door.

He was just leaving when he heard: "Your whore isn't home."

Gollum had emerged from his cave. He was once tall, almost six foot six, but now so stooped with age that his eyes were level with Blomkvist's. His face and neck were splotched with dark liver spots. He was in his pyjamas and a brown dressing gown, leaning on a cane. He looked like a Central Casting nasty old man.

"What did you say?"

"I said that your whore isn't home."

Blomkvist stepped so close that he was almost nose to nose with Harald Vanger.

"You're talking about your own daughter, you fucking pig."

"I'm not the one who comes sneaking over here in the night," Harald said with a toothless smile. He smelled foul. Blomkvist sidestepped him and went down the road without looking back. He found Vanger in his office.

"I've just had the pleasure of meeting your brother," Mikael said.

"Harald? Well, well, so, he's ventured out. He does that a couple of times a year."