Blomkvist followed the shoreline to the southeast, but the way was so interrupted by ravines and so grown over with juniper shrubs that it was all but impassable. He went back to the cabin and started back on the road to Hedeby. According to the map there was a path through the woods to something called the Fortress. It took him twenty minutes to find it in the overgrown scrub. The Fortress was what remained of the shoreline defence from the Second World War; concrete bunkers with trenches spread out around a command building. Everything was overrun with long grass and scrub.

He walked down a path to a boathouse. Next to the boathouse he found the wreck of a Pettersson boat. He returned to the Fortress and took a path up to a fence-he had come to Östergården from the other side.

He followed the meandering path through the woods, roughly parallel to the fields of Östergården. The path was difficult to negotiate-there were patches of marsh that he had to skirt. Finally he came to a swamp and beyond it a barn. As far as he could see the path ended there, a hundred yards from the road to Östergården.

Beyond the road lay the hill, Söderberget. Blomkvist walked up a steep slope and had to climb the last bit. Söderberget’s summit was an almost vertical cliff facing the water. He followed the ridge back towards Hedeby. He stopped above the summer cottages to enjoy the view of the old fishing harbour and the church and his own cottage. He sat on a flat rock and poured himself the last of the lukewarm coffee.

Cecilia Vanger kept her distance. Blomkvist did not want to be importunate, so he waited a week before he went to her house. She let him in.

“You must think I’m quite foolish, a fifty-six-year-old, respectable headmistress acting like a teenage girl.”

“Cecilia, you’re a grown woman. You have the right to do whatever you want.”

“I know and that’s why I’ve decided not to see you any more. I can’t stand…”

“Please, you don’t owe me an explanation. I hope we’re still friends.”

“I would like for us to remain friends. But I can’t deal with a relationship with you. I haven’t ever been good at relationships. I’d like it if you would leave me in peace for a while.”

After six months of fruitless cogitation, the case of Harriet Vanger cracked open. In the first week of June, Blomkvist uncovered three totally new pieces of the puzzle. Two of them he found himself. The third he had help with.

After Berger’s visit in May, he had studied the album again, sitting for three hours, looking at one photograph after another, as he tried to rediscover what it was that he had reacted to. He failed again, so he put the album aside and went back to work on the family chronicle instead.

One day in June he was in Hedestad, thinking about something altogether different, when his bus turned on to Järnvägsgatan and it suddenly came to him what had been germinating in the back of his mind. The insight struck him like a thunderbolt out of a clear sky. He felt so confused that he stayed on the bus all the way to the last stop by the railway station. There he took the first bus back to Hedeby to check whether he had remembered correctly.

It was the first photograph in the album, the last picture taken of Harriet Vanger on that fateful day on Järnvägsgatan in Hedestad, while she had been watching the Children’s Day parade.

The photograph was an odd one to have included in the album. It was put there because it was taken the same day, but it was the only one of the photographs not of the accident on the bridge. Each time Blomkvist and (he supposed) everyone else had looked at the album, it was the people and the details in the pictures of the bridge that had captured their attention. There was no drama in the picture of a crowd at the Children’s Day parade, several hours earlier.

Vanger must have looked at the photograph a thousand times, a sorrowful reminder that he would never see her again.

But that was not what Blomkvist had reacted to.

It was taken from across the street, probably from a first-floor window. The wide-angle lens had caught the front of one of the floats. On the flatbed were women wearing glittering bathing suits and harem trousers, throwing sweets to the crowd. Some of them were dancing. Three clowns were jumping about in front of the float.

Harriet was in the front row of the crowd standing on the pavement. Next to her were three girls, clearly her classmates, and around and behind them were at least a hundred other spectators.

This is what Blomkvist had noticed subconsciously and which suddenly rose to the surface when the bus passed the exact same spot.

The crowd behaved as an audience should. Their eyes always follow the ball in a tennis match or the puck in an ice hockey rink. The ones standing at the far left of the photograph were looking at the clowns right in front of them. The ones closer to the float were all looking at the scantily clad girls. The expressions on their faces were calm. Children pointed. Some were laughing. Everyone looked happy.

All except one.

Harriet Vanger was looking off to the side. Her three friends and everyone else in her vicinity were looking at the clowns. Harriet’s face was turned almost 30° to 35° to her right. Her gaze seemed fixed on something across the street, but beyond the left-hand edge of the photograph.

Mikael took the magnifying glass and tried to make out the details. The photograph was taken from too great a distance for him to be entirely sure, but unlike all those around her, Harriet’s face lacked excitement. Her mouth was a thin line. Her eyes were wide open. Her hands hung limply at her sides. She looked frightened. Frightened or furious.

Mikael took the print out of the album, put it in a stiff plastic binder, and went to wait for the next bus back into Hedestad. He got off at Järnvägsgatan and stood under the window from which the picture must have been taken. It was at the edge of what constituted Hedestad’s town centre. It was a two-storey wooden building that housed a video store and Sundström’s Haberdashery, established in 1932 according to a plaque on the front door. He went in and saw that the shop was on two levels; a spiral staircase led to the upper floor.

At the top of the spiral staircase two windows faced the street.

“May I help you?” said an elderly salesman when Blomkvist took out the binder with the photograph. There were only a few people in the shop.

“Well, I just wanted to see where this picture was taken from. Would it be OK if I opened the window for a second?”

The man said yes. Blomkvist could see exactly the spot where Harriet had stood. One of the wooden buildings behind her in the photograph was gone, replaced by an angular brick building. The other wooden building had been a stationery store in 1966; now it was a health food store and tanning salon. Blomkvist closed the window, thanked the man, and apologised for taking up his time.

He crossed the street and stood where Harriet had stood. He had good landmarks between the window of the upper floor of the haberdashery and the door of the tanning salon. He turned his head and looked along Harriet’s line of sight. As far as he could tell, she had been looking towards the corner of the building that housed Sundström’s Haberdashery. It was a perfectly normal corner of a building, where a cross street vanished behind it. What did you see there, Harriet?

Blomkvist put the photograph in his shoulder bag and walked to the park by the station. There he sat in a pavement café and ordered a latte. He suddenly felt shaken.