increased risk of a further family member going missing within the near future.
While they were keeping an eye on the family of the women who had vanished from Sollentuna, two children were reported missing from Tyresö. Mikael and Felicia Kohler-Frost. The children of the well-known author, Reidar Frost.
Joona looks at the petrol gauge as he passes the Statoil filling station and a snow-covered lay-by.
He remembers talking to Reidar Frost and his wife Roseanna Kohler three days after their two children went missing. He didn’t mention his suspicions to them – that they had been murdered by a serial killer whom the police had stopped looking for, a murderer whose existence they had only managed to identify in theory.
Joona just asked his questions, and let the parents cling onto the idea that the children had drowned.
The family lived on Varvsvägen, in a beautiful house facing a sandy beach and the water. There had been several mild weeks and a lot of the snow had thawed. The streets and footpaths were dark and wet. There was barely any ice along the shoreline, and what remained was grey slush.
Joona remembers walking through the house, passing a large kitchen and sitting down at a huge white table next to a window. But Roseanna had closed all the curtains, and although her voice was calm her head was shaking the whole time.
The search for the children was fruitless. There had been countless helicopter searches, divers had been called in, and the water had been dragged for bodies. The surroundings had been searched by chain gangs of both volunteers and specialist dog units.
But no one had seen or heard anything.
Reidar Frost looked like a captured animal.
He just wanted to keep on searching.
Joona had sat opposite the two parents, asking routine questions about whether they had received any threats, if anyone had behaved oddly or differently, if they had felt they were being followed.
‘Everyone thinks they fell in the water,’ the wife had said, her head starting to shake again.
‘You mentioned that they sometimes climb out of the window after their bedtime prayers,’ Joona went on calmly.
‘Obviously, they’re not supposed to,’ Reidar said.
‘But you know that they sometimes creep out and cycle off to see a friend?’
‘Rikard.’
‘Rikard van Horn, number 7 Björnbärsvägen,’ Joona said.
‘We’ve tried talking to Micke and Felicia about it, but … well, they’re children, and I suppose we didn’t think it was that harmful,’ Reidar replied, gently laying his hand over his wife’s.
‘What do they do at Rikard’s?’
‘They never stay for long, just play a bit of Diablo.’
‘They all do,’ Roseanna whispered, pulling her hand away.
‘But on Saturday they didn’t cycle to Rikard’s, but went to Badholmen instead,’ Joona went on. ‘Do they often go there in the evening?’
‘We don’t think so,’ Roseanna said, getting up restlessly from the table, as if she could no longer keep her internal trembling in check.
Joona nodded.
He knew that the boy, Mikael, had answered the phone just before he and his younger sister had left the house, but the number had been impossible to trace.
It had been unbearable, sitting there opposite the children’s parents. Joona said nothing, but was feeling more and more convinced that the children were victims of the serial killer. He listened, and asked his questions, but he couldn’t tell them what he suspected.
If the two children were victims of this serial killer, and they were correct in thinking that he would soon try to kill one of the parents as well, they had to make a choice.
Joona and Samuel decided to concentrate their efforts on Roseanna Kohler.
She had moved out to live with her sister in Gärdet, in north-east Stockholm.
The sister lived with her four-year-old daughter in a white apartment block at 25 Lanforsvägen, close to Lill-Jan’s Forest.
Joona and Samuel took turns keeping watch on the building at night. For a week, one of them would sit in their car a bit further along the road until it got light.
On the eighth day Joona was leaning back in his seat, watching the building’s inhabitants get ready for night as usual. The lights went off in a pattern that he was starting to recognise.
A woman in a silver-coloured padded jacket went for her usual walk with her golden retriever, then the last windows went dark.
Joona’s car was parked in the shadows on Porjusvägen, between a dirty white pickup and a red Toyota.
In the rear-view mirror he could see snow-covered bushes and a tall fence surrounding an electricity substation.
The residential area in front of him was completely quiet. Through the windscreen he watched the static glow of the streetlamps, the pavements and unlit windows of the buildings.
He suddenly started to smile to himself when he thought about the dinner he had eaten with his wife and little daughter before he drove out there. Lumi had been in a hurry to finish so she could carry on examining Joona.
‘I’d like to finish eating first,’ he suggested.
But Lumi had adopted her serious expression and talked to her mother over his head, asking if he was brushing his teeth himself yet.
‘He’s very good,’ Summa replied.
She explained with a smile that all of Joona’s teeth had come through, as she carried on eating. Lumi put a piece of kitchen roll under his chin and tried to stick a finger in his mouth, telling him to open wide.
His thoughts of Lumi vanished as a light suddenly went on in the sister’s flat. Joona saw Roseanna standing there in a flannel nightdress, talking on the phone.
The light went out again.
An hour passed, but the area remained deserted.
It was starting to get cold inside the car when Joona caught sight of a figure in the rear-view mirror. Someone hunched over, approaching down the empty street.
Joona slumped down slightly in his seat and followed the figure’s progress in the rear-view mirror, trying to catch a glimpse of its face.
The branches of a rowan tree swayed as he passed.
In the grey lights from the substation Joona saw that it was Samuel.
His colleague was almost half an hour early.
He opened the car door and sat down in the passenger seat, pushed the seat back, stretched out his legs and sighed.
‘OK, so you’re tall and blond, Joona … and it’s really lovely being in the car and everything. But I still think I’d rather spend the night with Rebecka … I want to help the boys with their homework.’
‘You can