‘Sounds like a cleaning agent.’

‘Where do I start?’

‘On what?’

A police car advanced along Trondheimsveien with sirens blaring. The sweeping blue lights did not reach into the darkness beneath the bridge. The noise did, however, and they sat in silence until the vehicle accelerated towards Carl Berner and disappeared.

‘There are actually only three possibilities,’ Einar said quietly as he drank the rest of the cold coffee. ‘If we take for granted that she’s telling the truth.’

He took off the mittens and carefully broke the cardboard beaker open along the seam. He licked the dregs from the inside and folded it up neatly before tucking it into a well-used plastic carrier bag from the Rema supermarket chain.

‘First of all, there could be some mistake with the tests.’

‘That doesn’t seem to be the case. Her father, Jan Morell, you know …’

‘I know who Jan Morell is.’

‘For a man with no internet connection or fixed abode, you’re remarkably well informed, Einar.’

‘Newspapers,’ he said tersely, shifting his backside a little. ‘Great things. They’re lying about all over the place and can be used for so many purposes. Just because you get to know most things hours after everyone else, doesn’t mean you don’t know.’

Selma smiled. Einar liked to see Selma smile. He persuaded himself that she kept this particular smile just for him, a mixture of admiration and love he had once encountered from so many people, but after all that had happened, now only had the strength to accept from her and her alone.

‘Hege learned of the case on Monday,’ Selma said. ‘Her father has used the time since then wisely. With his money and energy a lot can be resolved PDQ. It doesn’t seem that there’s anything wrong with the tests.’

‘Then we’re down to two scenarios. Either she ingested this substance by accident, through her own fault or someone else’s, or else she’s been sabotaged.’

Silence reigned between them.

Einar Falsen felt a headache coming on. It was just his luck. After four good days when only his rheumatism had grumbled a little, especially his left hip, it was as if barbed wire was tightening around his head. It must be that blasted phone she always had with her, even though she had switched it off.

‘An accident is the more likely scenario,’ he said, closing his eyes. ‘Sabotage the more exciting.’

She did not reply.

‘You have to start by freeing yourself,’ he said slowly.

‘What do you mean?’

‘Empty your mind. Pretend you don’t know anything whatsoever about the Chinese girl or her father. Begin with a completely blank sheet of paper.’

‘That could be a bit difficult, since Hege’s the best cross-country skier in Norway and has received wall-to-wall coverage for years and years.’

‘A blank sheet, Mariska,’ he said, opening his eyes again. ‘A completely blank sheet. When you speak to her for the first time, you have to try to wipe the slate completely clean. Ask the obvious questions. Even if you think you know the answers. You’re not going to put a roof on the building yet. You must first dig down into the very foundations.’