“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 Sundström’s Haberdashery. Harriet was in seventeen of them.

She and her classmates had arrived at Järnvägsgatan 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° 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 Järnvägsgatan.

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 Järnvägsgatan. She changed and at about 2:00 helped to set the table for the banquet that evening.