Einar really ought to be in hospital, but that wasn’t going to happen. On the rare occasions when he was really unwell, or when the winter was unusually harsh, she had found a place for him in a shelter. He had stayed there for three days at most, and all he did was to watch episode after episode of Law & Order SVU in the common room until he left as soon as his legs could carry him.

Moving him would be pointless. He could sleep off the infection and the madness, as he had done before, or else he could die in the course of the night.

Einar Falsen had once been a police officer. An extremely capable police officer. At the beginning of the noughties he had led a special group combating the sexual abuse of children. The internet had seriously begun to be an arena for crimes, and the battle had to be intensified. A man was brought in following a formal complaint by two devastated couples in Romsås. Their children, a boy of five and a girl of eight, had shown a worrying change in behaviour in the past few weeks. Both had in the end told them in snatches what the detainee had done. The children knew him only as Uncle Bjørn.

Uncle Bjørn had given them lots of things. But he had also taken a great deal from them, and when the police received the complaints, they conducted an immediate search of the man’s residence. His name was actually Anders and he was in his early forties. Single and childless.

His apartment could have been used as an operating theatre. Sparkling clean. Neat, tidy and without as much as an innocent porn magazine in a drawer in the bedside cabinet. In the basement they found nothing but two pairs of skis, an old kicksled and four winter tyres. The man also had a computer. It contained not the slightest trace of viewing the increasing number, and borderline legal, pages of spicy adult entertainment.

Which in itself was so suspicious that Einar refused to give up. Uncle Bjørn was arrested on a Friday afternoon, a well-known move to get around the rule then in force about making an appearance for remand in custody within twenty-four hours. They could stretch it out all the way to Monday before going to court. On Sunday evening the police had still drawn a blank. The stories of the two Romsås children, unclear and slightly disjointed, were sufficient for an experienced policeman like Einar Falsen. But they were miles from guaranteeing a remand order. Far less a subsequent prosecution.

Then Uncle Bjørn’s grandmother phoned.