Joona thinks that mysteries are only mysteries until you have discounted all the impossibilities.

When he was in hospital Margot told him that the videos had been recorded long before the murders took place.

Maria Carlsson owned nothing but black underwear, but the seams of the tights she was wearing when she died were different to the ones in the video. The spoon found in the tub of ice cream in Susanna Kern's home wasn't the same one that was in the video, and the post- mortem will probably show that Sandra Lundgren hadn't injected herself with insulin in her thigh on the day she was murdered.

Cla.s.sic stalking. The women have been watched and their behaviour mapped over a long period.

Joona leans against the walls as he walks through the house towards the kitchen. He tells himself that he'll call the police in Huddinge and follow up the previous day's events as soon as he's had something to eat.

He drinks some more water, puts coffee on, and looks in the fridge, where he finds half a pizza and a tub of yoghurt.

On the kitchen table, next to Erik's empty coffee cup, are printouts relating to an almost ten-year-old case that was tried in Sdertlje District Court.

Joona eats the cold pizza as he reads the verdict, the post-mortem a.n.a.lysis and the entire preliminary investigation report.

The old murder has striking similarities to the recent ones.

The vicar of the parish of Salem, Rocky Kyrklund, was arrested and convicted for the murder of a woman called Rebecka Hansson.

Joona was pretty out of it yesterday when Erik was taking care of him, but he can remember what Erik said. Margot Silverman had asked him to go and talk to a guy who had been sentenced to secure psychiatric care. She wanted Erik to find out if he had any accomplices or disciples.

She must have meant Rocky Kyrklund.

Margot's thinking along the right lines, Joona thinks, bracing his arms on the table as he stands up again. He walks barefoot into the back garden, sits down on the cushionless garden swing for a while, then walks over to the shed.

On one end is a water-damaged dartboard. Joona opens the door and gets out the cushions for the swing-seat. He goes back to the shed to close the door, but stops and looks at the neat arrangement of DIY tools and gardening implements on the wall.

In the turning circle at the end of the road an ice-cream van starts to play its jingle. Joona picks up an old Mora knife with a red wooden handle and tests its weight, then takes down a smaller knife in a plastic sleeve, walks out and shuts the door behind him.

He puts the smaller knife on the ground beside the swing-seat, then stands in the middle of the lawn and weighs the Mora knife in his right hand. He changes his grip, tries to find some sort of balance, a sense of lightness, puts the knife down by his hip and stretches out the other arm, feeling it tug at his wound.

Cautiously he tries to perform a kata against two opponents with the knife. He doesn't follow through on all the elements, but his legs still feel frustratingly heavy when he finishes.

Joona twists his body and moves his legs in the reverse order, leaving his attacker's torso unguarded. He performs a diagonal cut, starting at the bottom, blocks the second attacker's hand and diverts the force of the a.s.sault as the knife moves downward, then glides out of danger.

He repeats the pattern of movements, slowly, perfectly balanced. His hip hurts, but his level of concentration is the same as before.

The different elements of the kata are only complicated because they don't come naturally, but against untrained opponents they can be extremely effective. In nine coordinated movements the attackers are disarmed and rendered harmless. It works like a trap if anyone chooses to attack, the trap is sprung.

Katas and shadow-boxing can never replace sparring and real-life situations, but they're a way to get the body used to the movements, and, by repet.i.tion, train the body to think that certain movements belong together.

Joona rolls his shoulders, finds his balance, hits out a few times, follows through with his elbow, then repeats the kata, but faster this time. He performs the vertical cut, deflects the imaginary attack, changes grip, but drops the knife in the gra.s.s.

He stops and straightens his back. Listens to the birdsong and the wind in the trees. He takes some deep breaths, bends over, picks up the knife and blows some gra.s.s off it, and finds its centre of gravity. Then he takes the knife in his right hand, throws it past the hammock at the dartboard, which wobbles, and the old darts come loose and fall off into the gra.s.s.

Someone claps, and he turns round and sees a woman in the garden. She's tall and blonde, and is watching him with a calm smile on her face.

63.

The woman looking at Joona has a self-aware but relaxed posture, reminiscent of a mannequin. Her arms are slender and her hands very freckly. She's wearing make-up, but not too much, tasteful. It looks like she might be blushing slightly.

Joona bends down and picks up the second knife from the ground, weighs it in his hand, then throws it over his shoulder towards the dartboard. It ends up in the branches of the weeping birch and falls to the gra.s.s next to the shed. She claps her hands again and walks over to him, smiling.

'Joona Linna?' she asks.

'It's not easy to see with a beard like this, but I think so,' he replies.

'Erik said you were confined to bed, and-'

The veranda door opens and Erik comes out into the garden with a worried look on his face.

'You should be careful with that hip until we've had it X-rayed,' he says.

'It's fine,' Joona says.

'I gave him cortisone in-'

'So you said,' the smiling woman interrupts. 'It seems to have worked.'

'This is Nelly,' Erik says. 'She's my closest colleague ... an excellent psychologist, the best in the country for traumatised children.'

'That's all empty flattery,' she smiles, shaking Joona's hand.

'How do you feel?' Erik asks.

'Fine,' he replies quietly.

'The penicillin will kick in properly tomorrow, you'll feel much stronger,' Erik says, smiling at Joona's tight clothes.

Joona groans as he sits down on the swing-seat. The others sit down beside him and they swing together gently. The springs creak and the cushions give off a damp, musty smell.

'Did you read the report of the preliminary investigation?' Erik asks after a while.

'Yes,' Joona says, glancing at him.

'I went and talked to Rocky this morning ... he's had terrible problems with his memory since the accident, but he was willing to try hypnosis ...'

'You hypnotised him?' Joona asks with interest.

'I wasn't sure if it would work, given the damage to brain tissue and his epileptic attacks ...'

'But he was receptive?' Joona asks, leaning his head back and looking up at the sky.

'Yes, but it wasn't easy working out what were real memories ... Rocky used to take a lot of drugs in those days, and some of the things he said under hypnosis which ought to have been proper memories sounded more like nightmares ... delirium.'

'G.o.d, that's difficult,' Nelly said, stretching her ankles.

Erik stands up, making the swing-seat move again.

'I was really only going to ask about the murder of Rebecka Hansson to find out if he had an accomplice,' he says. 'But under hypnosis it sounded more like he was completely innocent.'

'In what way?' Joona asks.

'Rocky keeps returning to a man he calls the preacher ... the unclean preacher.'

'That sounds creepy,' Nelly says.

'And now, all of a sudden, he remembers that he's got an alibi for the night of the murder,' Erik says in a low voice.

'He said that under hypnosis?' Joona asks.

'No, he was awake then.'

'Is there anyone who can confirm the alibi?'

'Her name is Olivia Toreby ... he remembered it at the time, but he's probably already forgotten it again,' Erik says, looking away.

'An alibi,' Nelly says.

'It's worth checking out, anyway,' Erik says.

'Have you spoken to Margot about this?' Joona asks.

'Of course.'

'Psychologists lead, one-nil,' Nelly says, slapping the cushion beside her to get him to sit down again.

Erik does so, and they spend a little while swinging, drifting off to the sound of the slow creaking of the metal springs, the birdsong, and some children playing in a nearby garden.

Then Erik's mobile buzzes on the cushion. It's Margot, and Joona takes the call.

'I presume you've checked criminal records, any previous suspicions and the police database?'

'Good to hear that you're feeling better,' Margot's rough voice says.

'The murderer may have done time, or simply been out of the country for all these years,' Joona goes on. 'I've got pretty good contacts with Europol and-'

'Joona, I can't discuss the preliminary investigation with you,' she interrupts.

'No, but I was just trying to say that nine years is one h.e.l.l of a long cooling off period for a-'

'OK, now I understand ... I understand what you mean, but Rocky Kyrklund's alibi doesn't stand up.'

'You found her?'

'Olivia Toreby had no idea what we were talking about. She was living in Jnkping at the time, and we can't see any connection between her and Rocky Kyrklund.'

'So you still think he had an apprentice? That he's mixed up in the murders?'

'That's why I'm calling Erik,' Margot says calmly. 'I want him to go back and ask Rocky properly about accomplices.'

'I'll pa.s.s you over to him,' Joona says, and hands over the phone.

While Erik is talking to Margot, Joona goes and picks up the knives and puts them back in the shed. He rests against the handle of a lawnmower for a moment. There's a small wasps' nest up by the roof, and in the far corner a homemade toy truck behind some folding chairs.

When he comes out again Erik is no longer on the phone, and has stretched out next to Nelly.

'Do you normally phone witnesses to ask about alibis?' Erik asks him.

'It depends,' Joona replies.

'I just mean ... You don't know if people are prepared to get involved,' Erik says. 'You don't know if people tell the truth when the police phone them so many years later.'

'No,' Joona says.

'I need to talk to her if I'm going to be able to go back to Rocky and look him in the eye,' Erik says.

64.

Joona wanted to go with Erik to talk to Olivia Toreby, but accepted that it was too soon. Erik gave him some more penicillin, another cortisone injection in his hip, and made sure he took 50mg of topiramate to forestall further migraines.

Nelly gets in the pa.s.senger seat, and as Erik drives off he looks in the rear-view mirror and sees Joona sit down on the swing-seat again.

'Shall I drive you home?' Erik asks.

'Didn't you say she lived in Jnkping?'

'Apparently she moved to Eskilstuna five years ago.'

'That's about an hour away, isn't it?'

'Yes.'