'But I don't understand why,' Joona persists.

'Buy a book on Swedish law.'

A strand of blonde hair blows across Sara's face, and she brushes it aside with one finger and raises her eyebrows as Joona starts to speak.

'According to chapter twenty-four, paragraph twenty,' he says, 'a prosecutor can revoke the decision to remand a suspect in custody if that decision is no longer justified.'

'Bravo,' she smiles. 'But there's a clear risk that Kyrklund will evade the course of justice, and a tangible danger that he would commit further offences.'

'But we're only talking about minor narcotics offences, punishable by a year's imprisonment at most ... and it's extremely doubtful that possession could even be proven.'

'You said it wasn't his jacket over the phone,' she says in a bright voice.

'And that the reason for holding him in custody in no way warrants this degree of intrusion into his life.'

'Suddenly it feels like I'm standing on the steps of the City Court holding fresh custody negotiations with a former police officer ...'

'I can arrange for supervision,' Joona says, following her down the steps.

'It doesn't work like that, as you well know.'

'I understand that, but he's ill and needs constant medical attention,' Joona says.

She stops and lets her eyes roam over his face.

'If Kyrklund needs a doctor, the doctor can come to prison.'

'But if I were to say that this is a particular treatment that can't be carried out in prison ...'

'Then I'd say you were lying.'

'I can get a medical certificate,' Joona persists.

'Go ahead, but I'm pressing charges next Tuesday.'

'I'll appeal.'

'Nice try,' she smiles, and starts walking again.

100.

Joona is sitting on one of the rear pews in Adolf Fredrik Church. A girls' choir is rehearsing for a concert up at the front. The choir leader gives them the right note and the teenagers start to sing O viridissima virga.

Joona sinks into memories of the long, light nights in Nattavaara after Summa's death. Sunlight floods through the arched windows of the church, mixed with autumn leaves and stained gla.s.s.

The choir pauses after a few minutes, the girls take out their mobiles, gather in groups and walk through the aisles, chatting as they go.

The door to the porch opens and closes quickly. The churchwarden looks up from her book, then carries on reading.

Margot comes in with two heavy plastic bags in her hands. They hit the pew as she squeezes in next to Joona. Her stomach has swollen so much that it presses again the shelf for hymnbooks.

'I really am sorry,' Margot says in a half-whisper. 'I know you don't want to believe it, but take a look at this.'

With a sigh she lifts one of the bags on to her lap and pulls out a printout showing a fingerprint match. Joona quickly reads through the various parameters of the comparison, then checks the first-level details himself, and sees the similarities in the lines and patterns.

There are three perfectly defined fingerprints, and the match with Erik Maria Bark is one hundred per cent.

'Where were the prints found?' Joona asks.

'On the little porcelain deer's head that was in Susanna Kern's hand.'

Joona gazes out into the nave. The choir is gathering once more, the choir leader claps her hands to get their attention.

'You asked for evidence before,' Margot continues. 'These fingerprints are evidence, aren't they?'

'In a judicial sense,' he says in a low voice.

'The searches are still going on,' she says. 'We've found our serial killer.'

'Have you?'

Margot puts the bag containing material from the preliminary investigation on Joona's lap.

'I really wanted to believe you, and the idea of the preacher,' she says, leaning back and breathing hard.

'You should,' Joona replies.

'You met Rocky, I arranged for you to be able to question him,' she says, with a hint of impatience. 'You said you needed to do that before you could find this unclean preacher.'

'He doesn't remember anything now.'

'Because there isn't anything to remember,' she concludes.

The choir starts singing, and the girls' voices fill the church. Margot tries to make herself more comfortable and tucks her plait over her shoulder.

'You traced Erik to Smland,' Joona says.

'The rapid response team stormed a charter bus and found his phone tucked between two seats.'

'Oops,' Joona says drily.

'He hasn't put a foot wrong so far, he's staying out of the way like a professional,' she says. 'It's almost as if he's been given advice about what to do.'

'I agree,' Joona says.

'Has he contacted you?' Margot asks.

'No,' Joona replies simply.

He looks down at the other bag, still on the floor between them.

'Is that my pistol?'

'Yes,' she replies, pushing the bag towards him with her foot.

'Thanks,' Joona says, gazing down into it.

'If you carry on looking for the preacher, I have to remind you that you're not doing so on my orders,' Margot says, starting to squeeze out of the pew again. 'You haven't received any material from me, and we never met here do you understand?'

'I'm going to find the murderer,' Joona says quietly.

'Fine, but we can't have any more contact ...'

Joona pulls out his pistol, under cover of the pew, ejects the magazine in his lap, pulls the bolt back, checks the mechanism, trigger and hammer, then puts the safety catch back on and reinserts the magazine.

'Who the h.e.l.l uses a Colt Combat?' Margot asks. 'I'd have backache within a week.'

Joona doesn't reply, just tucks the pistol into his shoulder holster and slips the spare magazine in his jacket pocket.

'When are you going to accept that Erik might be guilty?' she asks roughly.

'You'll see that I'm right,' he says, meeting her gaze with icy calmness.

101.

Nelly Brandt is sitting at her computer, typing. Her neatly made-up face is blank with concentration as her blonde hair curls softly over her shoulders. She's wearing a beige suede skirt and a gold polo-necked sweater that sits tightly round her body.

When Joona comes in and says h.e.l.lo to her she doesn't answer, just stands up and goes over to the window and picks a deep pink flower from the bush outside.

'There you go,' she says, giving the flower to Joona. 'With my heartfelt thanks for the magnificent detective work-'

'I can understand that-'

'Hang on,' she interrupts. 'I need to pick another one.'

She reaches out and picks a second flower, and hands it to Joona.

'For the whole of the Swedish police force,' she says. 'f.u.c.king impressive ... No, I'm going to have to go out and dig up the whole bush ... if you open the boot of your car, then-'

'Nelly, I know the police have got it wrong,' Joona says.

It's as if all the air goes out of her, she sits down at the desk and rests her head on her hands, tries to say something but can't get the words out.

'I'm still trying to find the real murderer,' Joona goes on. 'But I need someone who can take over where Erik left off.'

'I'd be happy to help,' she says, looking up at him.

'Can you hypnotise people?'

'No,' she laughs, taken aback. 'I thought ... that's not my area, I actually find it a bit creepy.'

'Do you know anyone who could help me?'

She twists the engagement ring on her freckled finger a couple of times and tilts her head.

'Hypnosis is tricky,' she says bluntly. 'But there are a few people with a good reputation ... Not that that's the same thing as being brilliant. It's like a generally applicable algorithm: the reputation of the best people in any field goes down to compensate for brilliance.'

'You mean there's no one as good as Erik?'

She laughs, flashing her white teeth.

'Nowhere near as good ... even if he's not exactly doing much for his reputation right now.'

'Is there someone I could talk to?'

'Anna Palmer here is supposed to be pretty good. It depends what you're after. She hasn't got Erik's experience when it comes to psychological trauma and states of shock, of course.'

Nelly leads Joona along the corridor, but after a little while she slows down and asks him if she's in danger.

'I can't answer that,' Joona replies honestly.

'My husband's working late all week.'

'You should ask for police protection.'

'No, not police protection, this is all too much ... It's just that we noticed that the lock at the back of the house was damaged yesterday.'

'Have you got someone you can go and stay with?'

'Yes, of course,' she says, blushing slightly.

'Do that, until this is over.'