Yngve couldn’t help but admire the Tollefsens’ house. Although it was somewhat run down, it had to be worth a fortune, he thought, even in a small place like Fredheim. It had so much potential, with its steep roof, its old wooden floorboards and a kitchen that was bigger than his living room. The house was so huge it could easily accommodate at least two families. On the upper floor there were bedrooms and cupboards everywhere. It was a perfect place to hide things.

Åse would have loved this place, he thought.

He found himself standing in front of the large mirror in the hall, when Therese came over.

‘I just spoke to Weedon’, she said. ‘Tobias’s phone has either been turned off or it has run out of juice. We only have its last position.’ She pointed to the floor they were standing on. ‘Here.’

‘So he turned off his phone before he left,’ Yngve said.

‘Maybe,’ Therese said. ‘We have to get hold of his phone records. See who he was in contact with last night.’

Yngve was looking at Tobias’s picture, the one Even had sent him. Tobias looked like any other teenager – unkempt, pimply, his forehead kind of greasy. He wore a cap on his head and stared at the camera with an almost offended expression. He’d had the same look on his face when Yngve had been here and talked to him on the night of Børre Halvorsen’s murder.

Could killers be that detached? Yngve wondered. Of course they could, he answered himself. There were sociopaths everywhere. Even kids of fifteen.

‘Mork?’ came a voice from upstairs.

‘Yes?’

‘You need to take a look at this.’

Yngve looked at Therese for a second, then rushed up the stairs. They entered Tobias’s room to find a technician standing by the desk, holding a key chain in his hands.

‘I found this in one of the drawers,’ he said.

The chain had three keys on them. Yngve heard Frode Lindgren’s voice in his head: The key chain has a blue-and-white string on it. This fit the description perfectly.

Yngve looked at Therese. She seemed to be lost in thought for a moment.

‘What is it?’ he said.

‘I just don’t get it,’ she said. ‘Isn’t it incredibly stupid to keep something that might connect you to the murders in your own bedroom?’

‘Maybe he is stupid,’ Yngve said.

‘I don’t understand what he’s up to. Why not take the keys with him, or at least hide them carefully? Why leave them here for us to find? Surely he would have known that we would come looking for evidence?’

‘He’s only fifteen,’ Yngve said. ‘Maybe he just didn’t think that far.’