Yngve looked down and blinked. The rain made his hands slippery. But he still had a firm grip on the drainpipe, and there were only six or seven more feet to the edge of the roof. He placed his boot on the bracket again but this time pushed his toes into it as hard as he could. And slowly, inch by inch, he was able to pull himself upwards. Soon he was able to reach the gutter. He stretched out and got a good grip of it. Then he slung one leg onto the roof, and with a final effort made it up safely.

Vapour was pouring out of his mouth. What the hell are you doing? You’re sixty-three years old. Are you trying to give yourself a heart attack?

‘I’m breathing,’ he said out loud. ‘Trying to, at least.’

No one could hear him up here in the noisy rain. Wet and cold, Yngve glanced around. Below one of the ambulances still had its blue lights on. They danced on the school walls, on the trees around the building. Yngve knew that his uniform jacket had reflective strips that shone in the dark, that he probably looked like a skeleton silhouette up here. But then it occurred to him that not just anyone could do what he’d just done. Certainly, it wasn’t a fine display of strength and agility, but you needed a bit of both to be able to get up on a roof like that.

The roof itself was almost flat, which made moving around easy. The surface was covered with gravel. In the dim morning light Yngve could see it was littered with pine needles and dead branches, brought here by the wind.

He paused for a moment, trying to think like the killer. He or she must have been preoccupied with getting away without being detected.

Taking small, careful steps, Yngve made it over to the other side of the roof. He couldn’t see any houses nearby that had windows facing the school; there were only trees, an open field of grass, then another cluster of trees. Behind that was a kindergarten, which Yngve knew hadn’t been open last night. The chances of anyone having seen anything, at least on this side of the school, were slim.