Jon, Reilly and Axel had been friends for the best part of a couple of decades. Axel was the dominant one of the trio and Reilly was easily led. Jon - well Jon was vulnerable. Something had happened to them all at the end of the previous year and Jon had recently been in a mental hospital, but now, at the beginning of autumn, Axel and Reilly were taking him for a weekend at Dead Water Lake.
The three young men went out in a boat and Jon went over the side. Neither Axel nor Reilly made any attempt to help him and they didn't report his disappearnace until the following moring - and even then they said that he'd gone for a walk in the forst forest and had not returned.
If you're expecting a police procedural then this book might disappoint. Inspector Sejer and Jakob Skarre are there - and Sejer has a new dog - but their presence is almost incidental. It's almost as though Fossum needed a couple of policemen for the story and these two were available. They were convenient policemen to use in what is really a psychological thriller rather than a 'whodunnit'.