When Erik met Rocky Kyrklund, his face was criss-crossed with red scars from the accident, his arm was in plaster, and his hair had just started to grow again after several operations. Rocky was a large man with a booming voice. He was almost two metres tall, broad-shouldered, with big hands and a thick neck.

Sometimes he would faint, falling off his chair, knocking over the flimsy table holding gla.s.ses and a jug of water, and hit his shoulder on the floor. But sometimes his epileptic attacks were almost invisible. He just seemed a bit subdued and distant, and afterwards he couldn't remember what they had been talking about.

Erik and Rocky got on fairly well. The priest was undeniably charismatic. He somehow managed to give the impression of speaking straight from the heart.

Erik leafs through the private journal in which he made notes during their conversations. The various subjects can be traced from one session to the next.

Rocky had neither admitted nor denied the murder; he said he couldn't remember Rebecka Hansson at all, and couldn't explain why his fingerprints had been found in her home, or how her blood came to be on his shoes.

During the best of their conversations, Rocky would circle the small islands of memories in an attempt to discern a bit more.

Once he said that he and Rebecka Hansson had had intercourse in the sacristy, albeit interrupted. He could remember details, such as the rough rug they had been lying on. An old gift from the young women of the parish. She had begun to menstruate, leaving a small bloodstain, like a virgin, he said.

During the following conversations he couldn't remember any of this.

The conclusion of the examination was that the crime had been committed under the influence of severe mental disturbance. The team believed that Rocky Kyrklund suffered from a grandiose, narcissistic personality disorder with elements of paranoia.

Erik leafs past a circled note, 'paying for s.e.x + drug abuse', in the journal, followed by some ideas for medication.

Naturally he shouldn't have had an opinion on the matter of guilt, but as time pa.s.sed Erik became convinced that Rocky was guilty, and that his mental disorder const.i.tuted a serious risk of further crimes.

During one of their last sessions, Rocky was talking about a ceremony to mark the end of the school year in a church decked out with spring greenery, when he suddenly looked up at Erik and said he hadn't murdered Rebecka Hansson.

'I remember everything now, I've got an alibi for the whole of that evening,' he said.

He wrote down the name Olivia, and an address, then gave the sheet of paper to Erik. They carried on talking, and Rocky began to speak in broken fragments, then fell completely silent, looked at Erik, and suffered a severe epileptic attack. Afterwards Rocky didn't remember anything, he didn't even recognise Erik, just kept whispering about wanting heroin, saying he could kill a child if only he was given thirty grams of medical diacetylmorphine in a bottle with an unbroken seal.

Erik never took Rocky's claim of an alibi seriously. At best it was a lie; at worst Rocky could have bribed or threatened someone to support the alibi.

Erik threw away the sc.r.a.p of paper, and Rocky Kyrklund was found guilty and sentenced to secure psychiatric care, with severe restrictions on any parole application.

And nine years later a woman is murdered in Bromma in a way that was reminiscent of Rebecka Hansson's murder, Erik thinks, closing the file bearing Rocky's name.

Aggressive violence directed at the face, neck and chest.

But, on the other hand, murders of this sort aren't altogether unusual. They can be triggered by anything from the jealousy of an ex-husband, aggression linked to Rohypnol and anabolic steroids, so-called honour killings, or a pimp making an example of a prost.i.tute trying to break away from him.

The only concrete connection is that Susanna Kern was left at the scene of the murder with her hand covering her ear, just like Rebecka Hansson was found on the floor with her hand round her own neck.

Perhaps Susanna Kern merely got tangled up in the belt of her kimono during the struggle.

The parallels certainly aren't unambiguous, but they are there, and they're forcing Erik to do something he should have done a long time ago.

He puts the file in his desk drawer and looks up the number of senior consultant Simon Casillas at Karsudden Hospital once more.

'Casillas,' the man answers in a voice like dried leather.

'Erik Maria Bark from the Karolinska.'

'h.e.l.lo again.'

'I've checked my diary, and I could actually squeeze in a visit.'

'A visit?'

The sound of a squash court is audible in the background, a ball hitting the wall, the squeak of shoes.

'I'm taking part in a research project for the Osher Centre at the Inst.i.tute which involves us following up on old patients, right across the spectrum ... which means I'm going to have to interview Rocky Kyrklund.'

Before they end the conversation Erik hears himself babble about the fabricated research project, about health-service funding, tax declarations, online CBT, and someone called Doctor Stnkel.

He slowly puts his phone down on the desk. Watches the little screen turn black as it slips into dormancy. The room is perfectly still. His leather seat creaks quietly like a moored boat. Through the open window he can hear the hiss of an evening shower approach across the gardens.

He bends forward and rests his elbows on the desk, leans his head on his hands and asks himself what on earth he's doing. What did I just say? he thinks. And who the h.e.l.l is Stnkel?

This could be a crazy idea, he knows that. But he also knows he has no choice. If Rocky's alibi was genuine, then he must be released, even if that would mean a media frenzy and a miscarriage of justice.

Erik skims through the logbook. There are no notes about an alibi, but towards the end one page has been torn out. He leafs forward, then stops. From that last session with Rocky there's a faint note in pencil that Erik doesn't remember. In the middle of the page, it says 'a priest with dirty clothes' across the lines, then the remainder of the book is blank.

He stands up and goes out into the kitchen to find something to eat. While he walks through the library he repeats to himself that he has to find out if Rocky's alibi was real.

If it was genuine, then this new murder could be connected to the old one, and Erik will have to confess everything.

19.

Saga Bauer is driving slowly through the vast campus of the Karolinska Inst.i.tute. As she approaches Retzius vg 5, she turns into the deserted car park and stops in front of the empty building.

Even though she's tired and not wearing any make-up, hasn't washed her hair and is wearing baggy clothes, most people would probably say she was the most beautiful person they had ever seen.

Recently there's been something hungry and hunted about her appearance: the bright blue of her eyes makes her creamy white skin look radiant.

On the floor in front of the pa.s.senger seat is a green holdall containing underwear, a bulletproof vest and five cartridges of ammunition: .45 ACP, hollow-tipped.

Saga Bauer has been on sick leave from her job with the Security Police for more than a year, and she hasn't visited the boxing club in all that time.

The only time she's missed work was during Barack Obama's visit to Stockholm. She stood at a distance and watched the President's cortge. Being constantly on the lookout for threats is an occupational hazard. She remembers the tingle that ran through her body when she identified a potential vantage point from which to fire a rocket-propelled grenade, an unguarded window, but a moment later the danger had pa.s.sed and nothing had happened.

The Forensic Medicine Department is closed, all the lights in the red-brick building seem to be off, but a white Jaguar with a damaged front b.u.mper is parked on the path right in front of the entrance.

Saga leans to the side, opens the glove compartment, takes out the gla.s.s jar and leaves the car. The air is mild and smells of freshly mown gra.s.s. She feels her Glock 21 bouncing under her left arm, and can hear a faint sloshing sound from the jar as she walks.

Saga has to clamber across the flowerbed to get past Nils hlen's car. The thorns of the wild rose make a scratching sound as they let go of her military trousers. The branches sway and a few rose petals drift to the ground.

The lock of the front door is prevented from clicking shut with the help of a rolled-up information leaflet.

She's been here enough times before to find her way. The grit on the poorly cleaned floor crunches as she heads down the corridor towards the swing-door.

She can't help smiling when she looks at the jar, and the cloudy liquid, the particles circling round.

The memory flashes through her, and her free hand goes involuntarily to one of the scars he left on her face, the deep cut just below her eyebrow.

Sometimes she thinks he must have seen something special in her, that that was why he spared her life, and sometimes she thinks that he simply considered death too easy he wanted her to live with the lies he had made her believe, in the h.e.l.l he had created for her.

She'll never know.

The only thing that is certain is that he chose not to kill her, and she chose to kill him.

She thinks of the darkness and the deep snow as she walks down the empty corridor of the Forensic Medicine Department.

'I hit him,' she whispers to herself.

She moistens her mouth, and in her mind's eye sees herself firing and hitting him in the neck, arm and chest.

'Three shots to the chest ...'

She changed her magazine and shot him again when he'd fallen into the rapids, she held the flare up and saw the cloud of blood spread out around him. She ran along the bank, shooting at the dark object, and carried on firing even though the body had been carried off by the current.

I know I killed him, she thinks.

But they never found his body. The police sent divers under the ice, and checked both banks with sniffer-dogs.

Outside the office is a neat metal sign bearing his name and t.i.tle: Nils hlen, Professor of Forensic Medicine.

The door is open, and the slight figure is sitting at his neat desk reading the newspaper with a pair of latex gloves on his hands. He's wearing a white polo-neck shirt under his white coat, and his pilot's sungla.s.ses flash as he looks up.

'You're tired, Saga,' he says amiably.

'A bit.'

'Beautiful, though.'

'No.'

He puts the newspaper down, pulls off the gloves and notices the quizzical look in her eyes.

'To save getting ink on my fingers,' he says, as though it were obvious.

Saga doesn't answer, just sets the jar down in front of him. The chopped-off finger moves slowly in the alcohol, through a cloud of wispy particles. A swollen and half-rotten index finger.

'So you think that this finger belonged to ...'

'Jurek Walter,' Saga says curtly.

'How did you get hold of it?' Nils hlen asks.

He picks up the jar and holds it up to the light. The finger falls against the inside of the gla.s.s as if it were pointing at him.

'I've spent more than a year looking ...'

To start with Saga Bauer borrowed sniffer-dogs and walked up and down both banks of the river, from Bergasjn all the way to Hysingsvik on the Baltic coast. She followed the sh.o.r.eline, combed the beaches, studied the currents of Norrfjrden all the way down to Vsterfladen, and made her way out to every island, talking to anyone who went fishing in the area.

'Go on,' hlen said.

She looks up and meets his relaxed gaze behind the shimmering surface of his sungla.s.ses. His latex gloves are lying on the desk in front of him, inside out, in two little heaps. One is quivering slightly, either from a draught or because of the rubber contracting.

'This morning I was walking along the beach out at Hgmars,' she explains. 'I've been there before, but I gave it another go ... the terrain on the north side is quite tricky, a lot of forest on the cliffs at the headland.'

She thinks of the old man walking towards her from the other direction with an armful of silver-grey driftwood.

'You've gone quiet again.'

'Sorry ... I b.u.mped into a retired church warden ... he said he'd seen me the last time I was there, and asked what I was looking for.'

Saga went with him to the inhabited part of the island. Less than forty people live there. The warden's house is tucked behind the white chapel and freestanding bell tower.

'He said he found a dead body on the sh.o.r.e towards the end of April ...'

'A whole body?' hlen asks in a low voice.

'No, just the torso and one arm.'

'No head?'

'No one can live without a torso,' she says, and can hear how agitated her voice sounds.

'No,' hlen replies calmly.

'The warden said the body must have been in the water all winter, because it was badly swollen, and very heavy.'

'They look terrible,' hlen said.

'He brought the body back through the forest in his wheelbarrow, and laid it on the floor of the tool-shed behind the chapel ... but the smell drove his dog mad, so he had to take it to the old crematorium.'

'He cremated it?'

She nods. The crematorium had been abandoned for decades, but in the middle of the overgrown foundations was a sooty brick oven with a chimney. The warden used to burn rubbish in the oven, so he knew it worked.

'Why didn't he call the police?' hlen asked.

Saga thinks of the way the churchwarden's house stank of fried food and old clothes. His neck was streaked with dirt and the bottles of home-brew in the fridge had dirty marks from his fingers.