Sterling launches its new Silver Oak imprint with Swedish authors Anders Roslund and Börge Hellström's suspenseful thriller, Three Seconds. They have responded jointly in the third person.

In Three Seconds, you continually blur the line between cops and criminals.

Society creates a picture of two types of people, but reality is neither black nor white, there's an enormous gray zone. One day you are a perpetrator, the next a victim. For example, Hellström has committed many crimes: assault, theft, fraud, burglary. But he's also been the victim of many crimes. As a child, he suffered sexual abuse. He has been assaulted and robbed. He was both the perpetrator and the victim. Was he good or evil? Who is the perpetrator and who is the victim, or are they both?

How do you share the co-writing duties?

We fight... a lot. But we have one rule we always respect. Whenever we split up for the day, we always do that as friends. We're very open about most things. But there is one thing we will never reveal: who does what in our work process. We believe that if we talked about who did what, our collaboration would suffer. But what we can say is that the process is divided into three stages of about eight months each: research, followed by story development, and then the writing itself, a cycle of about two years.

What sparked your interest in setting much of the action inside a Swedish prison?

Roslund has worked for many years as a journalist in prisons and as a probation officer for prisoners with serious convictions. Hellström has been in prison and was a drug user for many years. So together we have a vast reservoir of knowledge from two different angles.

The issues you tackle obviously require intensive research. How do you go about it?

A prerequisite was that it had to be right. And that depends so much on the contacts we've made and earned along the way. To be able to sit with men who have been inside for 30 years, to see how they hide drugs and needles with the help of bits of elastic in maximum security prisons, requires a trust that we have worked long and hard for. To be able to meet policemen who work with criminals in the gray area called covert human intelligence—people who commit crimes so that other crimes can be solved—to learn about where they hold their secret meetings, or how you pay people who aren't supposed to exist. All these meetings are essential to us in the writing of every book.