Until the Eighties, Oslo was a rather boring town, but it's changed a lot, and is now much more cosmopolitan. If I go downtown, I visit the harbour to see the tall ships and the ferries, and to admire the modern architecture such as the Opera House or the new Astrup Fearnley Museum on the water's edge.

My influence is probably more from American crime writers than any Europeans. And I hardly read any Scandinavian crime before I started writing myself. I wasn't a great crime reader to begin with.

What do we mean by 'crazy?' What do we mean by 'mad?' At what point is a person just different and at what point can we call it a disease and say that they are not responsible for their actions? Or are we all slaves to the chemical processes that go on in our brains?

Everything you do leaves traces, doesn't it. The life you've lived is written all over you, for those who can read.

I've read that it's the smell some carnivores use to find their prey. Imagine the trembling victim trying to hide, but knowing that the smell of its own fear will kill it.

I don't think I'll ever feel as famous or as popular as I felt when I was a 17-year-old soccer player in Modle. Only about 20,000 people live there and 12,000 of them come to every game. Running onto the pitch each week was just the most fantastic feeling. Nothing can beat that.

In most sports, your brain and your body will cooperate... But in rock climbing, it is the other way around. Your brain doesn't see the point in climbing upwards. Your brain will tell you to keep as low as possible, to cling to the wall and not get any higher. You have to have your brain persuading your body to do the right movements.